Dexamethasone Suppression for 18F-FDG PET/CT to Localize ACTH-Secreting Pituitary Tumors

Posted on September 26, 2023 by MaryO

Abstract

Background

18Fluorine-Fluoro-deoxy-glucose (18F-FDG) positron emission tomography (PET) is widely used for diagnosing various malignant tumors and evaluating metabolic activities. Although the usefulness of 18F-FDG PET has been reported in several endocrine diseases, studies on pituitary disease are extremely limited. To evaluate whether dexamethasone (DEX) suppression can improve 18F-FDG PET for the localization of adrenocorticotropic hormone-secreting adenomas in the pituitary gland in Cushing’s disease (CD).

Methods

We included 22 patients with CD who underwent PET imaging before and after DEX administration. We compared the success rates of PET before and after DEX suppression, magnetic resonance imaging (MRI), and bilateral inferior petrosal sinus sampling (BIPSS). We determined the final locations of adenomas based on intraoperative multiple-staged resection and tumor tissue identification using frozen sections. Standardized uptake value (SUV) were analyzed to confirm the change of intensity of adenomas on PET.

Results

Twenty-two patients were included (age at diagnosis: 37 [13–56] years), and most were women (90.91%). Pituitary adenomas compared to normal pituitaries showed increased maximum SUV after DEX suppression but without statistical significance (1.13 versus. 1.21, z=-0.765, P = 0.444). After DEX suppression, the mean and maximum SUV of adenomas showed a positive correlation with nadir cortisol levels in high-dose DEX suppression test (Rho = 0.554, P = 0.007 and Rho = 0.503, P = 0.017, respectively). In reference sites, mean SUV of cerebellum was significantly decreased (7.65 vs. 6.40, P = 0.006*), but those of the thalamus and gray matter was increased after DEX suppression (thalamus, 8.70 vs. 11.20, P = 0.010*; gray matter, 6.25 vs. 7.95, P = 0.010*).

Conclusion

DEX suppression did not improve 18F-FDG PET/CT localization in patients with CD.

Introduction

Cushing’s disease (CD) is a rare endocrine disease that results from chronic exposure to high cortisol levels because of adrenocorticotropic hormone (ACTH)-secreting pituitary tumors and is associated with increased morbidity and mortality. It represents approximately 80% of all cases of endogenous hypercortisolism [1,2,3]. Accurate localization of primary lesions in CD leads to improved remission rates and reduced adverse events following surgery [4, 5]. A biochemical remission rate of 90–100% has been reported when tumors are localized before surgery, but it can decrease to 50–60% when surgery is performed when the location of the tumor is unknown in patients with CD [6,7,8].

Currently, magnetic resonance imaging (MRI) is the gold standard for detecting pituitary adenomas. Nevertheless, modern MRI modalities, including dynamic or volumetric sequences, can reliably detect corticotrophic adenomas in 50–90% cases of CD [9,10,11,12]. This indicates that complementary imaging strategies are required to improve the localization of primary lesions in CD.

One of the most characteristic features of corticotrophic adenomas is a compromised response to negative glucocorticoid feedback, which defines glucocorticoid resistance [13]. ACTH activates the adrenal glands to synthesize and secrete cortisol, which in turn negatively modulates the release of ACTH from the pituitary gland and corticotrophin-releasing hormone (CRH) and vasopressin from the hypothalamus [1]. In CD, a corticotrophic tumor is only partially sensitive to the inhibitory feedback exerted by cortisol, which in turn is not regulating its own production and secretion of ACTH, resulting in both excessive ACTH and cortisol levels. Glucocorticoid resistance is caused by multiple factors including glucocorticoid receptor availability, splice variant expression and affinity, and imbalanced glucocorticoid receptor signaling [14, 15].

Radioactive 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) often demonstrates increased fluorodeoxyglucose (FDG) uptake in nonfunctioning and hormone-secreting pituitary adenomas [16,17,18]. In large observational studies of whole-body 18F-FDG positron emission tomography (PET) scans, incidental sellar 18F-FDG uptake was found in < 1% of cases, and this sign is highly specific for pituitary adenomas [19,20,21]. 18F-FDG PET imaging can detect up to 40% of corticotropinomas, some as small as 3 mm, and the rate of PET detection of corticotropinomas can be increased by CRH stimulation [9, 22].

Here, we evaluated whether DEX suppression could improve the localization of ACTH-secreting adenomas using 18F-FDG PET/CT in patients with CD. The rationale for this is as follows. FDG uptake of corticotrophic adenomas is less suppressed than that of normal pituitary glands after DEX suppression due to glucocorticosteroid resistance.

Materials and methods

Study design and population

In this retrospective cohort study, we enrolled all patients with CD who underwent two rounds of 18F-FDG-PET/CT before and after 8-mg DEX suppression and pituitary MRI before surgery. Total 22 patients were included in this study, of which thirteen had bilateral inferior petrosal sinus sampling (BIPSS) results. All patients were diagnosed with CD by staff of the Department of Endocrinology and/or Neurosurgery at Severance Hospital between 2014 and 2015. The diagnosis of CD was confirmed based on biochemical test results, including the cortisol, 24-hour urine free cortisol (24 h UFC), and serum ACTH levels, overnight dexamethasone suppression test (ON DST) results, and high-dose dexamethasone suppression test (HD DST) results.

Immediate remission was defined as hypocortisolism (serum cortisol level < 1.8 µg/dL) within the first 7 days after surgery. Delayed remission was defined as the achievement of hypocortisolism within 6 months, although immediate remission was not confirmed. If patients showed elevated postoperative cortisol levels and needed additional treatment within 6 months after surgery, we defined them as having persistent disease [23,24,25].

A serum cortisol concentration > 1.8 µg/dL for 8 h in the morning after 1 mg of DEX was given at midnight was considered to be a positive result in the ON DST [26]. Suppression of the serum cortisol level by > 50% for 6 h after 2 mg of DEX was administered for 2 days was defined as the suppression on the HD DST [26]. The final diagnosis was confirmed using surgical pathology and clinical follow-up.

Endocrinological evaluation

All laboratory analyses were performed at the Department of Laboratory Medicine, Severance Hospital. Preoperative cortisol and 24 h UFC were measured by chemiluminescence immunoassay using an automated UniCel DXC880i Synchron analyzer (Beckman Coulter, Pasadena, CA, USA; coefficient of variation [CV] ± 15 nmol/L at < 100 nmol/L and ± 15% at > 100 nmol/L). Preoperative ACTH levels were analyzed by electrochemiluminescence immunoassay using the Roche Cobas 6000 analyzer (Roche Diagnostics GmbH, Mannheim, Germany; CV ± 2.0 pmol/L at < 20 pmol/L and ± 10% at > 20 pmol/L).

The serum cortisol concentration at 8:00 am the following day after 1 mg of DEX was administered at midnight was considered positive on the ON DST. We determined the result as “suppression” by the cortisol level of < 1.8 µg/dL. A serum cortisol level suppressed by > 50% of the original level after 6 hourly administrations of 2 mg of DEX for 48 h was defined as suppression on the HD DST [27].

18F-FDG PET/CT evaluation

PET/CT was performed using a GEADVANCE PET scanner (GE, Milwaukee, WI, USA) after the intravenous injection of 7–9 mCi of 18F-FDG. All patients fasted for at least 6 h before the test. Emission scanning was continued for 15 min (4.25-mm axial spatial resolution, 4.8-mm transaxial spatial resolution). Transmission scans were performed for 8 min using triple Ge-68 rod sources to correct attenuation. Gathered data were reconstructed in a 128 × 128 × 35 matrix with a pixel size of 1.95 × 1.95 × 4.25 mm by means of a filtered back-projection algorithm employing a transaxial 8.5-mm Hanning filter and 8.5-mm axial ramp filter. Two specialists independently interpreted the encoded baseline PET images, and after a two-week period, they interpreted the encoded post DEX suppression PET images. Each specialist was blinded to MRI imaging, clinical characteristics, and surgical outcomes of these subjects. Each was tasked with determining whether the PET image indicated a “negative” or “positive” result for pituitary adenoma and its location on a high-resolution computer screen.

The scan after DEX suppression was performed 24 h after the oral administration of 8 mg of DEX using the same procedures as for the baseline PET/CT scan.

18F-FDG uptake analysis

The Region of interest (ROI) was drawn using MIM software (version 6.5, Software INc., Cleveland, OH, USA) (Fig. 1). PET images were reviewed by experienced by an experienced specialist. The pituitary gland was identified and a circular ROI was drawn. A fixed ROI with a 3-mm diameter was used for all patients. The ROI was placed on the lesion with the highest FDG uptake. If there was no significantly increased FDG uptake, the same sized circular ROI was drawn on the suspected adenoma location. For the normal pituitary gland, the same sized 3 mm ROI was used.

Fig. 1

figure 1

Images of ROI for pituitary adenoma on18F-FDG PET scan

Example of ROI definition in pituitary adenomas of 18F-FDG PET scan of the patients with CD. We draw the fixed circular ROI with a 3-mm diameter for pituitary adenomas (red circle) and normal pituitary gland (green circle)

ROI, Reason of interest; 18F-FDG PET, 18 F-fluorodeoxyglucose positron emission tomography; CD, Cushing disease

The mean standardized uptake value (SUVmean) and maximum SUV (SUVmax) for pituitary adenomas and normal pituitary glands were automatically measured using MIM, version 6.5 (Software Inc., Cleveland, OH, USA). The standardized uptake value (SUV) of the volume of interest was calculated as follows: (decoy-corrected activity (kBq) / volume (mL)) / (injected dose (kBq) / body weight (g)).

SUVmean and SUVmax of pituitary adenomas were divided into the SUVmean of normal pituitary glands for adjustment. We used the ratio of SUVmax to SUVmean to analyze the homogeneity of the pituitary adenomas.

MRI evaluation

All patients underwent pituitary MRI with a 3.0-Tesla scanner (Achieva, Philips Medical Systems, Best, the Netherlands). Imaging protocols included T1-weighted imaging, T2-weighted imaging, and delayed gadolinium-enhanced T1-weighted imaging. The extent, location, and sizes of the pituitary tumors were reviewed based on official records determined by radiologists.

Pituitary tumors were classified based on radiological findings using MRI of the sellar and parasellar regions. Type I refers to tumors < 1 cm in diameter limited to the sella. Type II tumors extend into the suprasellar space, < 1 cm from the diaphragm. Type III includes tumors extending into the suprasellar space > 1 cm from the diaphragm or sphenoid sinus and encroaching on the internal carotid arteries. Lastly, type IV refers to adenomas with obvious invasion into the cavernous sinus, as shown on MRI, and into the medial dural wall of the cavernous sinus, as confirmed during surgery.

BIPSS

Before surgery, BIPSS was performed to confirm the cause of CD and lateralize the tumors. A catheter was placed in patients using a unilateral femoral venous approach and 3 cc of blood was collected from the peripheral (P) and both inferior petrosal sinuses (IPS) [28]. CRH at a dose of 1 µg/kg was administered, and peripheral and petrosal samples were drawn after 5 and 10 min, respectively. The catheters and sheath were removed, and the groin was compressed under pressure until venous hemostasis was achieved.

The IPS:P prolactin ratio was calculated at each time point to confirm the accuracy of the inferior petrosal venous sampling. A value of ≥1.8 was considered successful IPS catheterization. The prolactin-normalized ACTH ratio was calculated by dividing the dominant ACTH IPS:P ratio by the concurrent and ipsilateral IPS:P prolactin ratio. A value of ≥1.3 was considered diagnostic of CD. An intersinus ACTH ratio of ≥1.4 either at baseline or after stimulation was used for lateralization of the pituitary adenoma [29].

Location of the adenoma

The final assignment of the true location of the pituitary adenoma was based on intraoperative multiple stage resection and tumor tissue identification using frozen sections. Surgically identified adenomas were histologically evaluated and stained for ACTH immunoreactivity. In cases of multiple specimens obtained during the procedure, the true location of the adenoma was assigned based on the original site of the specimen containing the adenoma [30].

Statistical analysis

Data are presented as medians (ranges) or numbers (percentages). The baseline characteristics of the patients were compared using Kruskal–Wallis’ test with Dunn’s procedure for nonparametric continuous variables. Categorical variables were compared using Fisher’s exact test. Spearman’s correlation coefficients were used to determine the correlation between FDG uptake and hormone levels. Wilcoxon’s signed-rank test was used to identify changes in the SUV after DEX administration.

The interobserver agreement for image analysis was assessed using κ statistics. κ values were categorized as follows: κ < 0.20 indicated poor agreement, κ of 0.21–0.40 indicated fair agreement, κ of 0.41–0.60 indicated moderate agreement, κ of 0.61–0.80 indicated good agreement, and κ > 0.81 indicated excellent agreement [31].

Statistical significance was set at a two-sided P < 0.05. All statistical analyses were performed using SPSS software (IBM Corp., Armonk, NY, USA).

Results

Patient characteristics

We enrolled all patients with CD who underwent two rounds of the 18F-FDG PET/CT with or without DEX suppression and sellar MRI before transsphenoidal adenectomy (TSA). Twenty-two patients were included (age at diagnosis: 37 [13–56] years), and most were women (90.91%). Patients’ baseline characteristics are shown in Table 1. There were 16 microadenomas and 6 macroadenomas. Immediate remission was achieved in 81.82% of the patients and delayed remission in 13.64%; one patient showed persistent disease after TSA. The median preoperative 24 h UFC, serum ACTH, and cortisol levels were 443.35 (93.00–4452.00) µg/day, 36.16 (6.00–92.00) pg/mL, and 18.55 (6.00–40.00) µg/dL. The size of pituitary adenomas on MRI was 7.85 (2.00–28.00) mm. The Ki-67 index of 47.06% of adenomas ranged from 1 to 2, that of 35.29% was below 1, and that of 17.65% was 2 or higher. Overall, 75.00% of the adenomas were classified as Knosp grade 0, 5.00% as grade 1, 5.00% as grade 3b, and 15.00% as grade 4. In total, 77.27% (17/22) of patients had an ACTH-staining adenoma. Only one patient showed unsuppressed cortisol levels on the HD DST.

Table 1 Patients’ imaging and clinical characteristics

MRI negative but PET positive case

Two patients showed negative MRI results, and one of them showed FDG uptakes on both 18F-FDG PET scans at baseline and after DEX suppression. A 26-year-old man visited our hospital complaining of weight gain and was diagnosed with ACTH-dependent CD. Cortisol secretion was suppressed on the HD DST; however, sellar MRI did not reveal any suspicious lesions. BIPSS revealed a central tumor (central/peripheral ACTH level of 36.25 after CRH stimulation) lateralized to the right side of the pituitary gland. The patient underwent 18F-FDG-PET/CT before and after DEX suppression to identify the primary lesions. Baseline PET/CT showed diffused FDG uptake with an SUVmax of 1.03 at the pituitary fossa but failed to localize the tumor. After DEX treatment, focal FDG uptake with an SUVmax of 1.06 remained at the right side of the pituitary fossa, which resulted in the successful localization of the corticotrophic adenoma. The MRI and PET/CT images of this case are presented in Fig. 2A–C. During TSA, the surgeon identified solid tumor-like tissues on the right side of the pituitary gland and successfully removed them. Results of pathology and ACTH immunohistochemistry were negative, but the patient achieved immediate biochemical remission and CD-related symptoms were relieved after surgery. We followed the patient for 98 months after the surgery and confirmed that he had lived without recurrence.

Fig. 2

figure 2

Images of a corticotroph with negative MRI but positive18 F-FDG PET/CT after DEX suppression

An MRI-negative adenoma was detected on 18F-FDG PET/CT at baseline and after DEX suppression. In this patient, the pituitary adenoma was visible on PET scans at baseline (B) and after DEX suppression (C) at the same location, as confirmed by the surgeon

A. Co-registered baseline 18F-FDG PET/CT and MRI images. Diffuse 18F-FDG uptake is detected in the pituitary fossa with an SUVmean of 0.86 and SUVmax of 1.03, but there was failure to localize the adenoma on baseline 18F-FDG PET/CT.

B. Co-registered 18F-FDG PET/CT and MRI images after DEX suppression. 18F-FDG uptake is not suppressed in the right side of the pituitary gland with an SUVmean of 1.03 and SUVmax of 1.06. 18F-FDG PET/CT after DEX suppression was successful in localizing the right-sided corticotrophic adenoma

C. MRI image. There is no suspicious lesion in the pituitary gland

ACTH, adrenocorticotropic hormone; MRI, magnetic resonance imaging; 18F-FDG, 18 F-fluorodeoxyglucose; PET/CT, positron emission tomography/computed tomography; DEX, dexamethasone; SUVmean, mean standardized uptake value; SUVmax, maximum standardized uptake value

Change of 18F-FDG uptake after DEX suppression

We included 18 pituitary adenomas that were successfully localized using PET/CT after DEX suppression, and analyzed the change of SUV for 15 adenomas, excluding outliers with SUV over 2.00. The results are presented in Fig. 3A and B. The SUVmean of adenomas did not changed after DEX suppression compared to normal pituitary glands (SUVmean of adenoma/SUVmean of normal pituitary glands: 1.13 [0.85–1.35] vs. 1.14 [0.87–1.39], z=-1.288, P = 0.198). DEX suppression increased SUVmax of adenomas compared to normal pituitary glands but without statistical significance (SUVmax of adenoma/SUVmean of normal pituitary glands: 1.13 [0.96–1.52] vs. 1.21 [0.97–1.56], z=-0.765, P = 0.444).

Fig. 3

figure 3

Changes in the SUVs of corticotrophs between18F-FDG PET/CT before and after DEX suppression

The SUVmean (A) and SUVmax (B) of corticotrophic adenomas are shown in this pairwise analysis. The SUVmean did not changed after DEX suppression from (z=-1.288, P = 0.198). The SUVmax of the corticotrophic adenoma increased from 1.13 to 1.21 (z=-0.765, P = 0.444). In this analysis, the SUVmean and SUVmax of pituitary adenomas were adjusted using the SUVmean of the normal pituitary gland. Colored plots and bars presented median and interquartile range in this figure. We presented the tumors with size larger than 5 mm and SUV adjusted by normal pituitary>1 for blue line

SUVmean, mean standardized uptake value; SUVmax, maximum standardized uptake value; DEX, dexamethasone; 18F-FDG, 18 F-fluorodeoxyglucose; PET/CT, positron emission tomography/computed tomography

In Fig. 3, the blue line indicates change in SUV of adenomas larger than 5 mm with higher FDG uptake than the surrounding pituitary parenchyma. For these adenomas, DEX suppression did not change the SUV (SUVmean of adenoma/SUVmean of normal pituitary glands: 1.31 [1.04–2.52] vs. 1.33 [1.05–2.38], z=-0.784, P = 0.433; SUVmax of adenoma/SUVmean of normal pituitary glands: 1.36 [1.02–2.61] vs. 1.40 [1.03–2.65], z=-1.022, P = 0.307).

The value of SUV increased in 73.33% adenomas, while the SUVmax increased in 66.67% compared with normal pituitary glands after DEX treatment.

Correlation between the hormone level and 18F-FDG uptake

Table 2 shows the results of the Spearman correlation analysis of the SUV with preoperative cortisol, ACTH, and nadir cortisol levels on the HD DST. On the baseline 18F-FDG PET scan, the SUVmax of the adenomas did not show any correlation with the levels of three hormones. The SUVmean of adenomas showed a positive correlation with nadir cortisol levels on the HD DST (P = 0.014) and preoperative ACTH levels, with marginal significance (P = 0.062). After DEX suppression, the SUVmax and SUVmean of adenomas had a positive correlation with moderate degrees of nadir cortisol on the HD DST (SUVmax: Spearman Rho = 503, P = 0.017; SUVmean: Spearman Rho = 0.554, P = 0.007).

Table 2 Correlation between FDG uptakes and hormone levels

FDG uptake of reference sites after DEX suppression

We evaluated the FDG uptake for five types of reference areas (normal pituitary gland, cerebellum, thalamus, white matter, and gray matter) (Table 3). Normal pituitary gland and white matter did not affect the unadjusted SUVmean by DEX suppression (all P >0.05). DEX significantly increased SUVmean of the thalamus and gray matter (thalamus, 8.70 [4.40–22.70] vs. 11.20 [6.40–17.5], P = 0.010*; gray matter, 6.25 [2.50–15.00] vs. 7.95 [5.00–11.90], P = 0.010*). However, SUVmean of the cerebellum significantly decreased after DEX administration (7.65 [4.50–10.80] vs. 6.40 [2.60–12.00], P = 0.006*).

Table 3 The change of FDG uptake for reference sites after DEX suppression in the patients with CD

Qualitative analysis by diagnostic modalities for CD

The qualitative results of localizing pituitary adenomas in CD patients are shown in Table 4 and Fig. 4. Only 13 patients had BIPSS results. The success rates were 90.91% for MRI and 84.62% for BIPSS.

Table 4 Qualitative analysis by diagnostic modalities for CD
Fig. 4

figure 4

Images for corticotroph adenomas that appear different for localization in18F-FDG PET/CT.

9 mm sized adenoma in the left lateral wing of pituitary gland. It was found in the left lateral wing of the pituitary gland, showing an 18F-FDG uptake in the pituitary fossa with an SUVmean of 1.04 and SUVmax of 1.07. However, after DEX suppression, the left side of the pituitary gland did not exhibit suppressed 18F-FDG uptake, with SUVmean 1.05 SUVmax 1.14

(A). Co-registered baseline 18F-FDG PET/CT and MRI images. (B). Co-registered 18F-FDG PET/CT and MRI images after DEX suppression. (C). MRI image

2 mm pituitary adenoma was detected at the left lateral wing, showing diffuse FDG uptake in the pituitary fossa with an SUVmean of 0.86 and SUVmax of 1.04. After DEX suppression, focal FDG uptake was observed, with SUVmean 0.87 and SUVmax 0.98. (D). Co-registered baseline 18F-FDG PET/CT and MRI images. (E). Co-registered 18F-FDG PET/CT and MRI images after DEX suppression. (F). MRI image

In baseline PET scans, the specialists agreed that pituitary adenomas were visible in 17 scans and not visible in 5 scans. They reached a consensus that the tumor was evident in two scans, but there was a discrepancy in their assessments of its location.

After DEX suppression, pituitary adenomas showed positive results in 16 scans and negative results in 5 scans. Specialists disagreed on the presence of pituitary adenomas in one case only.

Interobserver agreement for localizing adenomas was 0.872 (95%CI: 0.711, 1.033) for baseline PET/CT and 0.938 (95%CI: 0.762, 1.056) for post dexamethasone suppression PET/CT, confirming excellent interobserver agreements, and the result was judged reliable. Among the instances where both opinions agreed, there were no lesions that showed differences in visibility between scans before and after DEX administration. This meant that lesions were either consistently visible or invisible in both scenarios.

Discussion

We found that DEX suppression did not improve localization of ACTH-secreting pituitary adenomas using 18F-FDG PET/CT. Further, it did not significantly affect FDG uptakes in adrenocorticotrophic adenomas or normal pituitaries in patients with CD. The decision to administer 8 mg dexamethasone was based on the standard high-dose DST, which is internationally recommended for differentiating between ectopic ACTH secretion and CD [26]. This test involved comparing serum cortisol levels at 8 am before and after a single dose of 8 mg dexamethasone administered at 11 pm. Suppression of the serum cortisol level to less than 50% of the baseline value indicated a diagnosis of CD [32, 33]. Previous studies have reported that the 8-mg DST has a sensitivity of 90%, specificity of 100%, accuracy of 96.8%, positive predictive value of 100%, and negative predictive value of 95.5% [34, 35]. Our use of 8 mg dexamethasone was based on the theory that orally administering dexamethasone at this dose can effectively suppress cortisol levels in ACTH-secreting pituitary tumors.

We expected that FDG uptake by corticotrophic adenomas would not decrease after DEX administration in patients with CD, and this change may improve the ability to discriminate the tumor location from surrounding tissues on 18F-FDG PET. The SUVmax of pituitary adenomas adjusted for the normal pituitary gland increased from 1.13 to 1.21. However, this change was not statistically significant, and the success rate of localizing corticotrophic adenomas using 18F-FDG PET was not significantly improved after DEX suppression. If the FDG uptake of adenomas changed lesser compared to that of surrounding normal tissues after DEX suppression, the tumor could be more easily visualized because of the difference.

In addition, we attempted to evaluate FDG uptakes in other brain areas (cerebellum, thalamus, white matter, and gray matter) according to DEX administration in CD patients. SUVmean of the cerebellum decreased significantly, but that of the thalamus and gray matter increased after DEX suppression. DEX did not change FDG uptake in pituitary adenoma, normal pituitary, or white matter. In a previous study analyzing FDG PET in CD patients, researchers observed varying correlations between FDG uptake and blood cortisol concentration across different brain regions [35, 36]. Nevertheless, the examination did not include an analysis of FDG uptake in the pituitary gland. Additionally, no previous studies have explored the effects of high-dose dexamethasone suppression on brain glucose metabolism in individuals with CD. Further studies are needed to explain the change in FDG uptake after DEX administration in patients with CD.

18F-FDG PET/CT provides information regarding glucose metabolism in the brain in vivo and has been widely used to evaluate brain metabolism in clinical and research settings [37]. Here, the nadir cortisol level on the HD DST correlated with the SUVmean and SUVmax of pituitary adenomas on PET scans after DEX suppression. Cortisol secretion activity is thought to be associated with metabolic activity, and DEX administration altered this. Cortisol levels and FDG uptake in other regions of the brain are correlated in patients with CD, but the correlation between cortisol and FDG uptake in the pituitary glands and/or corticotrophic adenomas themselves has not been discussed [35, 36]. In our study, cortisol levels did not show a correlation with FDG uptake of corticotrophic adenomas, but after DEX suppression FDG uptake showed a correlation with the nadir cortisol level on the HD DST. This indicated that tumors in which cortisol secretion was less suppressed by on the HD DST showed higher FDG uptake than tumors with lower cortisol levels on the HD DST.

Although many studies have analyzed FDG uptake of brain tumors, reference sites defined in each study varied without a uniform standard. Gray matter, white matter, or adjacent tumor tissue was defined as a reference site [38,39,40]. We measured SUVmean of normal pituitary tissues, gray matter, white matter, thalamus, and cerebellum as possible references. We defined the SUVmean of normal pituitary tissues as a reference because the localization of adenomas requires an apparent difference between the adenoma and surrounding tissues.

Use of fixed ROI to measure FDG uptake caused partial volume effect in this study. However, lesions smaller than 5 mm with intense FDG uptake may still show increased FDG uptake, especially in tumors, albeit with lower SUV values compared with the actual values [41]. This study was performed because pituitary adenomas smaller than 5 mm with higher FDG uptake than the surrounding pituitary parenchyma have been observed in routine clinical practice. To control for the partial volume effect, the analysis was performed again for tumors which were larger than 5 mm and had higher FDG uptake than the surrounding pituitary parenchyma, and the results remained unchanged.

PET/CT has been explored as an alternative to or combined with MRI for the localization of corticotrophic adenomas. 18F-FDG PET/CT has a limited role in CD diagnosis, but CRH stimulation can increase its success rate [22, 42]. This study is important for increasing the effectiveness of PET using DEX. In addition, data on DEX effect on brain metabolism in patients with CD will be important for future studies.

Conclusions

DEX suppression did not improve the localization of 18F-FDG PET/CT in patients with CD. This is considered to have sufficient significance in an effort to increase the diagnostic value of 18F-FDG PET/CT.

Data Availability

All datasets generated and/or analyzed during the current study are not publicly available but are available from the corresponding author upon reasonable request.

Abbreviations

18F-FDG:
18F-fluorodeoxyglucose
PET/CT:
Positron emission tomography/computed tomography
DEX:
Dexamethasone
MRI:
Magnetic resonance imaging
BIPSS:
Bilateral inferior petrosal sinus sampling
CD:
Cushing’s disease
SUV:
Standardized uptake value
ACTH:
Adrenocorticotropic hormone
CRH:
Corticotrophin-releasing hormone
FDG:
Fluorodeoxyglucose
24hr UFC:
24-hour urine free cortisol
ON DST:
Overnight dexamethasone suppression test
HD DST:
High-dose dexamethasone suppression test
SUVmean :
Mean standardized uptake value
SUVmax :
Maximum standardized uptake value
P:
Peripheral
IPS:
Inferior petrosal sinuses
TSA:
Transsphenoidal adenectomy

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    Acknowledgements

    We would like to thank Editage (www.editage.co.kr) for English language editing.

    Funding

    The study was supported by the “Team Science Award” of Yonsei University College of Medicine (6-2022-0150).

    Author information

    Authors and Affiliations

    1. Endocrinology, Institute of Endocrine Research, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea

      Kyungwon Kim, Cheol Ryong Ku & Eun Jig Lee

    2. Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea

      Dong Kyu Kim

    3. Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea

      Ju Hyung Moon, Eui Hyun Kim & Sun Ho Kim

    Contributions

    Conception and design: EJL, CRK, KK. Acquisition of data: KK, DKK. Analysis and interpretation of data: KK. Drafting the article: KK. Administrative/technical/material support: JHM, EHK, SHK. Study supervision: EJL, CRK. Writing, review, and revision of the manuscript: KK, DKK, SHK, CRK. Final approval of the manuscript: CRK, EJL.

    Corresponding authors

    Correspondence to Cheol Ryong Ku or Eun Jig Lee.

    Ethics declarations

    Ethics approval and consent to participate

    The data were collected under the conditions of regular clinical care with approval from the ethics committee of our hospital, and the requirement for written informed consent was waived owing to its retrospective design (institutional review board number: 2023-0110-001).

    Consent for publication

    Not applicable.

    Competing interests

    The authors declare no conflicts of interest that could be perceived as prejudicing the impartiality of this study.

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    Electronic supplementary material

    Additional file 1 of Dexamethasone suppression for 18F-FDG PET/CT to localize ACTH-secreting pituitary tumors

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    Cite this article

    Kim, K., Kim, D.K., Moon, J.H. et al. Dexamethasone suppression for 18F-FDG PET/CT to localize ACTH-secreting pituitary tumors. Cancer Imaging 23, 85 (2023). https://doi.org/10.1186/s40644-023-00600-8

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    Keywords

    • 18F-FDG PET/CT
    • ACTH-secreting pituitary tumor
    • Cushing’s disease
    • Dexamethasone suppression
    • High-dose dexamethasone suppression test

    From https://cancerimagingjournal.biomedcentral.com/articles/10.1186/s40644-023-00600-8

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Cushing Syndrome Caused by an Ectopic ACTH-Producing Pituitary Adenoma of the Clivus Region

Posted on July 10, 2023 by MaryO

Abstract

Rationale:

Ectopic ACTH–producing pituitary adenoma (EAPA) of the clivus region is extraordinarily infrequent condition and merely a few reports have been reported to date.

Patient concerns:

The patient was a 53-year-old woman who presented with Cushing-like appearances and a soft tissue mass in the clivus region.

Diagnoses:

The final diagnosis of clivus region EAPA was established by clinical, radiological and histopathological findings.

Interventions:

The patient underwent gross total clivus tumor resection via transsphenoidal endoscopy.

Outcomes:

Half a year after surgery, the patient Cushing-like clinical manifestations improved significantly, and urinary free cortisol and serum adrenocorticotropin (ACTH) returned to normal.

Lessons:

Given the extreme scarcity of these tumors and their unique clinical presentations, it may be possible to misdiagnose and delayed treatment. Accordingly, it is especially crucial to summarize such lesions through our present case and review the literature for their precise diagnosis and the selection of optimal treatment strategies.

1. Introduction

Pituitary adenoma arises from the anterior pituitary cells and is the commonest tumor of the sellar region.[1] It makes up approximately 10% to 15% of all intracranial tumors.[2] Ectopic pituitary adenoma (EPA) is defined as a pituitary adenoma that occurs outside the sellar area and has no direct connection to normal pituitary tissue.[3] The most frequent sites of EPA are the sphenoid sinus and suprasellar region, and much less frequent sites including the clivus region, cavernous sinus, and nasopharynx.[4]

Hypercortisolism and the series of symptoms it leads to is termed Cushing syndrome (CS).[5] CS is classified into adrenocorticotropin (ACTH)-dependent and ACTH-independent CS depending on the cause, accounting for 80% to 85% and 15% to 20% of cases, respectively.[6] Pituitary adenoma accounts for ACTH-dependent CS 75% to 80%, while ectopic ACTH secretion accounts for the remaining 15% to 20%.[7] Ectopic CS is a very rare disorder of CS caused by an ACTH-secreting tumor outside the pituitary or adrenal gland.[8] It has been reported that ectopic ACTH–producing pituitary adenoma (EAPA) can occur in the sphenoid sinus, cavernous sinus, clivus, and suprasellar region,[9] with EAPA in the clivus region being extremely rare, and merely 6 cases have been reported in the English literature (Table 1).[10–15] Furthermore, as summarized in the Table 1, EAPA in the clivus area has unique symptoms, which may lead to misdiagnosis as well as delay in treatment. Therefore, we herein described a case of CS from an EAPA of the clivus region and reviewed relevant literature for the purpose of further understanding this extraordinarily unusual condition.

Table 1 – Literature review of cases of primary clival ectopic ACTH–producing pituitary adenoma (including the current case).

Reference Age (yr)/sex Symptoms Imaging findings Maximum tumor diameter (mm) Preoperative elevated hormone IHC Surgery RT Follow-up (mo) Outcome
Ortiz et al 1975[10] 15/F NA NA NA NA NA Right transfrontal craniotomy, NA Yes NA Symptomatic relief
Anand et al 1993[11] 58/F Anosphrasia, blurred vision, occasional left frontal headache, Routine radiographic evaluation revealed a clival tumor and nasopharyngeal mass with bone erosion. MRI demonstrated a Midline homogeneous mass. 30 ACTH ACTH in a few isolated cells Maxillotomy approach, GTR Yes 12 Symptomatic relief
Pluta et al 1999[12] 20/F Cushing syndrome MRI revealed a hypodense contrast-enhancing lesion. NA ACTH ACTH Transsphenoidal surgery, GTR No 18 Symptomatic relief
Shah et al 2011[13] 64/M Facial paresthesias, myalgias, decreased muscle strength, and fatigue CT imaging showed a clival mass. 21 ACTH ACTH NA, GTR No 7 Symptomatic relief
Aftab et al 2021[14] 62/F Transient unilateral visual loss MRI showed a T2 heterogeneously enhancing hyperintense lesion. 21 No ACTH Transsphenoidal resection, GTR NO 6 Symptomatic relief
Li et al 2023[15] 47/F Bloody nasal discharge, dizziness and headache CT revealed an ill-defined mass eroding the adjacent bone. MRI T1 showed a heterogeneous mass with hypointensity, hyperintensity on T2-weighted images and isointensity on diffusion-weighted images. 58 NA ACTH Transsphenoidal endoscopy, STR Yes 2 Symptomatic relief
Current case 53/F Headache, and dizziness, Cushing syndrome CT demonstrated bone destruction and a soft tissue mass. MRI T1 revealed irregular isointense signal, and MRI T2 showed isointense signal/slightly high signal. 46 ACTH ACTH Transsphenoidal endoscopy, GTR NO 6 Symptomatic relief
ACTH = adrenocorticotropin, CT = computed tomography, GTR = gross total resection, IHC = immunohistochemistry, MRI = magnetic resonance imaging, NA = not available, RT = radiotherapy, STR = subtotal resection.

2. Case presentation

A 53-year-old female presented to endocrinology clinic of our hospital with headache and dizziness for 2 years and aggravated for 1 week. Her past medical history was hypertension, with blood pressure as high as 180/100 mm Hg. Her antihypertensive medications included amlodipine besylate, benazepril hydrochloride, and metoprolol tartrate, and she felt her blood pressure was well controlled. In addition, she suffered a fracture of the thoracic vertebrae 3 month ago; and bilateral rib fractures 1 month ago. Physical examination revealed that the patient presented classical Cushing-like appearances, including moon face and supraclavicular and back fat pads, and centripetal obesity (body mass index, 25.54 kg/m2) with hypertension (blood pressure, 160/85 mm Hg).

Laboratory studies revealed high urinary free cortisol levels at 962.16 µg/24 hours (reference range, 50–437 µg/24 hours) and absence of circadian cortisol rhythm (F [0am] 33.14 µg/dL, F [8am] 33.52 µg/dL, F [4pm] 33.3 µg/dL). ACTH levels were elevated at 90.8 pg/mL (reference range, <46 pg/mL). The patient low-dose dexamethasone suppression test demonstrated the existence of endogenous hypercortisolism. High-dose dexamethasone suppression test results revealed that serum cortisol levels were suppressed by <50%, suggesting the possibility of ectopic ACTH-dependent CS. Serum luteinizing hormone and serum follicle stimulating hormone were at low levels, <0.07 IU/L (reference range, 15.9–54.0 IU/L) and 2.57 IU/L (reference range, 23.0–116.3 IU/L), respectively. Insulin-like growth factor-1, growth hormone (GH), prolactin (PRL), thyroid stimulating hormone, testosterone, progesterone and estradiol test results are all normal. Oral glucose tolerance test showed fasting glucose of 6.3 mmol/L and 2-hour glucose of 18.72 mmol/L; glycosylated hemoglobin (HbA1c) was 7.1%. Serum potassium fluctuated in the range of 3.14 to 3.38 mmol/L (reference range, 3.5–5.5 mmol/L), indicating mild hypokalemia.

High-resolution computed tomography (CT) scan of the sinuses revealed osteolytic bone destruction of the occipital clivus and a soft tissue mass measuring 20 mm × 30 mm × 46 mm (Fig. 1A). The mass filled the bilateral sphenoid sinuses and involved the cavernous sinuses, but the pituitary was normal. Cranial MR scan showed the T1W1 isointense signal and the T2W1 isointense signal/slightly high signal in the sphenoid sinus and saddle area (Fig. 1B–D). Bone density test indicated osteoporosis.

F1
Figure 1.: 

Radiological findings. (A) CT demonstrated bone destruction and a soft tissue mass on the occipital clivus (white arrow). (B) Axial view of the MR T1 revealed irregular isointense signal in the sphenoid sinus and saddle area (white arrow). (C and D) Axial view and sagittal view of the MR T2 showed isointense signal/slightly high signal in the sphenoid sinus and saddle area (black arrow). CT = computed tomography.

Subsequently, the patient underwent gross total clivus tumor resection via transsphenoidal endoscopy. During surgery, the tumor was found to be light red in color with a medium texture, and the tumor tissue protruded into the sphenoidal sinus cavity and eroded the clival area. Histologically, the tumor cells were nested, with interstitially rich blood sinuses and organoid arrangement (Fig. 2A). The tumor cells were relatively uniform in size, with light red cytoplasm, delicate pepper salt-like chromatin, and visible nucleoli (Fig. 2B). In addition, mitosis of tumor cells was extremely rare. Immunohistochemically, the neoplasm cells were diffuse positive for CK (Fig. 2C), CgA (Fig. 2D), ACTH (Fig. 2E), Syn and CAM5.2, with low Ki-67 labeling index (<1%) (Fig. 2F). Simultaneously, all other pituitary hormone markers like GH, thyroid stimulating hormone, PRL, luteinizing hormone, as well as follicle stimulating hormone were negatively expressed. On the basis of these medically historical, clinical, laboratorial, morphologic, and immunohistochemical findings, the final pathological diagnosis of an EAPA was established.

F2
Figure 2.: 

HE and immunohistochemical findings. (A) Histologic sections revealed morphologically homogeneous tumor cells in nests with a prominent and delicate vascularized stroma (H&E, × 200). (B) The tumor cells had fine chromatin with visible nuclei and rare mitoses (H&E, × 400). CK (C), CgA (D) and ACTH (E) immunohistochemically showed diffuse reactivity of the tumor cells (SP × 200). (F) The proliferation index is <1% on Ki-67 staining (SP × 200).

When evaluated 2 months after surgery, her Cushing-like characteristics had well improved, and her blood pressure was normal. Furthermore, her serum cortisol and ACTH returned to the normal levels. Six-month postoperative follow-up revealed that serum cortisol and ACTH were stable at normal levels, and no signs of tumor recurrence were detected on imaging.

3. Discussion

EAPA is defined as an ACTH-secreting ectopic adenoma located outside the ventricles, and has no continuity with the normal intrasellar pituitary gland.[9] ACTH promotes cortisol secretion by stimulating the adrenal cortical fasciculus. The clinical manifestations of hypercortisolism are diverse, and the severity is partly related to the duration of the cortisol increase.[8] Clival tumors are typically uncommon, accounting for 1% of all intracranial tumors. There are many differential diagnoses for clival lesions, including the most common chordoma (40%), meningioma, chondrosarcoma, astrocytoma, craniopharyngioma, germ cell tumors, non-Hodgkin lymphoma, melanoma, metastatic carcinoma, and rarely pituitary adenoma.[16] The commonest clival EPA is a PRL adenoma, followed by null cell adenoma, and the least common are ACTH adenoma and GH adenoma.[2] The clival EAPA is extremely unwonted, and only 6 other cases apart from ours have been reported in literature so far (Table 1).

The average age of the patients with these tumors was 48 years (range, 15–64 years). There was a obvious female predominance with a female-to-male prevalence ratio of 6:1. Only 2 patients (2/6, 33.3%) with reported clinical symptoms, including our patients, presented with overt clinical manifestations of CS. Compression of the mass on adjacent structures (e.g., nerves) may result in anosphrasia, visual impairment, headache, myalgias, decreased muscle strength, dizziness and facial sensory abnormalities. The diagnosis and localization of these tumors relied heavily on radiological imaging. Head MRI was the most basic method used for them detection, for localization adenomas and their invasion of surrounding structures to guide the choice of treatment and surgical options methods. Radiographic characteristics had been reported in 6 patients with EAPA in the clivus region. All of these patients (6/6, 100%) had initial positive findings of sellar MRI (or CT) identifying an ectopic adenoma before surgery. MR T1 was usually a low-intensity or isointense signal, while MR T2 was usually an isointense or slightly higher signal. The maximum diameter of the tumor was reported in 5 cases, with the mean maximum diameter was 35.2 mm (range, 21–55 mm) according to preoperative MRI and intraoperative observations. As summarized in Table 1, 4/5 clival EAPA cases secreted ACTH. Histologically, all cases (6/6, 100%) expressed ACTH scatteredly or diffusely.

The gold standard for the treatment of CS caused by EAPA was the surgical removal of EPA, which was essential to achieve remission and histological confirmation of the disease.[9] The most common method of EAPA resection in the clivus region was transsphenoidal sinus resection (4/6, 66.67%), followed by craniotomy (1/6, 16.67%) and maxillary osteotomy (1/6, 16.67%). Transsphenoidal endoscopic surgery allowed resection of the EAPA and manipulation of neurovascular structures and avoidance of cerebral atrophy, whereas craniotomy allowed full exposure of the suprasellar region, direct visualization or manipulation of the adenoma, and reduced the risk of postoperative CSF leak.[9] Both approaches had their advantages, and there was no consensus on which surgical approach was best for the treatment of EAPA in the slope area.[9] The choice of the best surgical approach was believed to be based on the condition of the adenoma, as well as the general condition of the patient and the experience of the surgeon.[9] As summarized in Table 1, most complete tumor resections were achieved regardless of the method chosen. A minority of patients underwent postoperative radiotherapy (3/7, 42.86%), and most of them had invasion of the surrounding bone tissue. All patients experienced effective postoperative relief of symptoms.

In summary, due to the rarity of this disorder, an accurate preoperative diagnosis of EAPA in the slope area is extremely challenging for the clinician or radiologist. The final precise diagnosis relies on a combination of clinical symptoms, imaging findings, histology and immunohistochemical markers. For this type of tumor, surgery is an effective treatment to relieve the clinical manifestations caused by tumor compression or hormonal secretion. The choice of postoperative adjuvant radiotherapy is mainly based on the presence of invasion of the surrounding bone tissue. Further cases may be necessary to summarize the clinical features of such lesions and to develop optimal treatment strategies.

Acknowledgments

We would like to thank the patient and her family.

Author contributions

Conceptualization: Yutao He.

Data curation: Ziyi Tang.

Formal analysis: Na Tang.

Methodology: Yu Lu, Fangfang Niu, Jiao Ye, Zheng Zhang, Chenghong Fang.

Writing – original draft: Yutao He.

Writing – review & editing: Yutao He, Lei Yao.

Abbreviations:

ACTH
adrenocorticotropin
CS
cushing syndrome
CT
computed tomography
EAPA
ectopic ACTH–producing pituitary adenoma
EPA
ectopic pituitary adenoma
GH
growth hormone
PRL
prolactin

References

[1]. Gittleman H, Ostrom QT, Farah PD, et al. Descriptive epidemiology of pituitary tumors in the United States, 2004-2009. J Neurosurg. 2014;121:527–35.

[2]. Karras CL, Abecassis IJ, Abecassis ZA, et al. Clival ectopic pituitary adenoma mimicking a Chordoma: case report and review of the literature. Case Rep Neurol Med. 2016;2016:8371697.

[3]. Bălaşa AF, Chinezu R, Teleanu DM, et al. Ectopic intracavernous corticotroph microadenoma: case report of an extremely rare pathology. Rom J Morphol Embryol. 2017;58:1447–51.

[4]. Zhu J, Wang Z, Zhang Y, et al. Ectopic pituitary adenomas: clinical features, diagnostic challenges and management. Pituitary. 2020;23:648–64.

[5]. Paleń-Tytko JE, Przybylik-Mazurek EM, Rzepka EJ, et al. Ectopic ACTH syndrome of different origin-diagnostic approach and clinical outcome. experience of one clinical centre. PLoS One. 2020;15:e0242679.

[6]. Sharma ST, Nieman LK, Feelders RA. Cushing’s syndrome: epidemiology and developments in disease management. Clin Epidemiol. 2015;7:281–93.

[7]. Aniszewski JP, Young WF Jr, Thompson GB, et al. Cushing syndrome due to ectopic adrenocorticotropic hormone secretion. World J Surg. 2001;25:934–40.

[8]. Mohib O, Papleux E, Remmelink M, et al. An ectopic Cushing’s syndrome as a cause of severe refractory hypokalemia in the ICU. Acta Clin Belg. 2021;76:373–8.

[9]. Sun X, Lu L, Feng M, et al. Cushing syndrome caused by ectopic adrenocorticotropic hormone-secreting pituitary adenomas: case report and literature review. World Neurosurg. 2020;142:75–86.

[10]. Ortiz-Suarez H, Erickson DL. Pituitary adenomas of adolescents. J Neurosurg. 1975;43:437–9.

[11]. Anand VK, Osborne CM, Harkey HL. Infiltrative clival pituitary adenoma of ectopic origin. Otolaryngol Head Neck Surg. 1993;108:178–83.

[12]. Pluta RM, Nieman L, Doppman JL, et al. Extrapituitary parasellar microadenoma in Cushing’s disease. J Clin Endocrinol Metab. 1999;84:2912–23.

[13]. Shah R, Schniederjan M, DelGaudio JM, et al. Visual vignette.s Ectopic ACTH-secreting pituitary adenoma. Endocr Pract. 2011;17:966.

[14]. Aftab HB, Gunay C, Dermesropian R, et al. “An Unexpected Pit” – ectopic pituitary adenoma. J Endocr Soc. 2021;5:A557–8.

[15]. Li Y, Zhu JG, Li QQ, et al. Ectopic invasive ACTH-secreting pituitary adenoma mimicking chordoma: a case report and literature review. BMC Neurol. 2023;23:81.

[16]. Wong K, Raisanen J, Taylor SL, et al. Pituitary adenoma as an unsuspected clival tumor. Am J Surg Pathol. 1995;19:900–3.

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Keywords:

clivus region; Cushing; Ectopic ACTH; like appearance; producing pituitary adenoma

From https://journals.lww.com/md-journal/Fulltext/2023/06230/Cushing_syndrome_caused_by_an_ectopic.32.aspx

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Severe Osteoporosis in a Young Man with Bilateral Cushing’s Syndrome

Posted on June 28, 2023 by MaryO

Abstract

Background

The diagnosis of Cushing’s syndrome is challenging; however, through the clinical picture and the search for secondary causes of osteoporosis, it was possible to reach the diagnosis of the case reported. There was an independent, symptomatic ACTH hypercortisolism manifested by typical phenotypic changes, severe secondary osteoporosis and arterial hypertension in a young patient.

Case presentation

A 20-year-old Brazilian man with low back pain for 8 months. Radiographs showed fragility fractures in the thoracolumbar spine, and bone densitometry showed osteoporosis, especially when evaluating the Z Score (− 5.6 in the lumbar spine). On physical examination, there were wide violaceous streaks on the upper limbs and abdomen, plethora and fat increase in the temporal facial region, hump, ecchymosis on limbs, hypotrophy of arms and thighs, central obesity and kyphoscoliosis. His blood pressure was 150 × 90 mmHg. Cortisol after 1 mg of dexamethasone (24.1 µg/dL) and after Liddle 1 (28 µg/dL) were not suppressed, despite normal cortisoluria. Tomography showed bilateral adrenal nodules with more severe characteristics. Unfortunately, through the catheterization of adrenal veins, it was not possible to differentiate the nodules due to the achievement of cortisol levels that exceeded the upper limit of the dilution method. Among the hypotheses for the differential diagnosis of bilateral adrenal hyperplasia are primary bilateral macronodular adrenal hyperplasia, McCune–Albright syndrome and isolated bilateral primary pigmented nodular hyperplasia or associated with Carney’s complex. In this case, primary pigmented nodular hyperplasia or carcinoma became important etiological hypotheses when comparing the epidemiology in a young man and the clinical-laboratory-imaging findings of the differential diagnoses. After 6 months of drug inhibition of steroidogenesis, blood pressure control and anti-osteoporotic therapy, the levels and deleterious metabolic effects of hypercortisolism, which could also impair adrenalectomy in the short and long term, were reduced. Left adrenalectomy was chosen, given the possibility of malignancy in a young patient and to avoid unnecessary definitive surgical adrenal insufficiency if the adrenalectomy was bilateral. Anatomopathology of the left gland revealed expansion of the zona fasciculate with multiple nonencapsulated nodules.

Conclusion

The early identification of Cushing’s syndrome, with measures based on the assessment of risks and benefits, remains the best way to prevent its progression and reduce the morbidity of the condition. Despite the unavailability of genetic analysis for a precise etiological definition, it is possible to take efficient measures to avoid future damage.

Peer Review reports

Background

Cushing’s syndrome may be exogenous or endogenous and, in this case, can be ACTH-dependent or independent. In the case reported, there was an independent, symptomatic ACTH hypercortisolism manifested by typical phenotypic changes, severe secondary osteoporosis and arterial hypertension in a young patient. Osteoporosis secondary to hypercortisolism occurs due to chronic reduction in bone formation, loss of osteocytes and increased reabsorption caused by intense binding of cortisol to glucocorticoid receptors present in bone cells [1]. In addition, excess cortisol impairs vitamin D metabolism and reduces endogenous parathyroid hormone secretion, intestinal calcium reabsorption, growth hormone release, and lean body mass [2]. Subclinical Cushing disease occurs in up to 11% of individuals diagnosed with early-onset osteoporosis and 0.5–1% of hypertension patients. [3] A cross-sectional study published in 2023 revealed a prevalence of 81.5% bone loss in 19 patients with Cushing’s syndrome [2]. The prevalence of osteopenia ranges from 60 to 80%, and the prevalence of osteoporosis ranges from 30 to 65% in patients with Cushing’s syndrome. Additionally, the incidence of fragility fractures ranges from 30 to 50% in these patients [4] and is considered the main cause of morbidity affecting the quality of life. The diagnosis is challenging, given the presence of confounding factors; however, through the clinical picture and the search for secondary causes of osteoporosis, it was possible to reach a syndromic diagnosis. Early identification of this syndrome, with measures based on the assessment of risks and benefits, remains the best way to prevent progression and reduce morbidity related to this disease [2].

Case presentation

A 20-year-old Brazilian male patient reported low back pain that had evolved for 8 months, with no related trauma. He sought emergency care and performed spinal radiographs on this occasion (03/2019). Due to the several alterations observed in the images, he was referred to the Orthopedics Service of the Hospital of Federal University of Juiz de Fora, which prescribed orthopedic braces, indicated physical therapy and was referred again to the Osteometabolic Diseases outpatient clinic of the Endocrinology and Rheumatology Services of the Hospital of Federal University of Juiz de Fora on 10/2019.

The radiographs showed a marked reduction in the density of bone structures, scoliotic deviation with convexity toward the left and reduction in the height of the lumbar vertebrae, with partial collapses of the vertebral bodies at the level of T12, L1, L2, L3 and L5, with recent collapses in T12 and L1, suggesting bone fragility fractures. The same can be seen in posterior magnetic resonance imaging (Fig. 1).

Fig. 1

figure 1

Radiography and Magnetic Resonance Imaging (MRI) of lumbosacral spine in profile

Bone scintigraphy on 08/2019 did not reveal hyper flow or anomalous hyperemia in the topography of the thoracolumbar spine, and in the later images of the exam, there was a greater relative uptake of the tracer in the lumbar spine (vertebrae T10–T12, L2–L4), of nonspecific aspect, questioning the presence of osteoarticular processes or ankylosing spondylitis.

It was also observed in the bone densitometry requested in October 2019, performed by dual-energy X-ray absorptiometry (DXA), low bone mineral density (BMD) in the lumbar spine, femoral neck and total femur, when comparing the results to evaluating the Z Score (Table 1).

Table 1 Dual-energy X-ray absorptiometry (DXA)

Thus, the diagnosis of osteoporosis was established, and treatment with vitamin D 7000 IU per week was started due to vitamin D3 insufficiency associated with the bisphosphonate alendronate 70 mg, also weekly. The patient had a past pathological history of fully treated syphilis (2018) and perianal condyloma with a surgical resection on 09/2017 and 02/2018. In the family history, it was reported that a maternal uncle died of systemic sclerosis. In the social context, the young person denied drinking alcohol and previous or current smoking.

On physical examination, there were no lentiginous skin areas or blue nevi; however, wide violet streaks were observed on the upper limbs and abdomen, with plethora and increased fat in the temporal facial region and hump (Fig. 2a, b), limb ecchymosis, hypotrophy of the arms and thighs, central obesity and kyphoscoliosis. Systemic blood pressure (sitting) was 150 × 90 mmHg, BMI was 26.09 kg/m2, and waist circumference was 99 cm, with no reported reduction in height, maintained at 1.55 m.

Fig. 2

figure 2

Changes in the physical examination. a Violet streaks on the upper limbs, b Violet streaks on abdomen

An investigation of secondary causes for osteoporosis was initiated, with the following laboratory test results (Table 2).

Table 2 Laboratory tests

Computed tomography of the abdomen with adrenal protocol performed on 08/13/2020 characterized isodense nodular formation in the body of the left adrenal and in the lateral portion of the right adrenal, measuring 1.5 cm and 0.6 cm, respectively. The lesions had attenuation of approximately 30 HU, showing enhancement by intravenous contrast, with an indeterminate washout pattern in the late phase after contrast (< 60%) (Fig. 3).

Fig. 3

figure 3

Computed tomography abdomen with adrenal protocol

After contact with the interventional radiology of the Hospital of Federal University of Juiz de Fora, catheterization of adrenal veins was performed on 10/2020; however, it was not possible to perform adequate lesion characterization due to obtaining serum cortisol levels that extrapolated the dilutional upper limit of the method (Table 3).

Table 3 Adrenal catheterization

The calculation of the selectivity index was 6.63 (Reference Value (RV) > 3), confirming the good positioning of the catheter within the vessels during the procedure. The calculated lateralization index was 1.1296 (VR < 3), denoting bilateral hormone production. However, as aldosterone was not collected from a peripheral vein, it was not possible to obtain the contralateral rate and define whether there was contralateral suppression of aldosterone production [5].

Due to pending diagnoses for a better therapeutic decision and Cushing’s syndrome in clear evolution and causing organic damage, it was decided, after catheterization, to make changes in the patient’s drug prescription. Ketoconazole 400 mg per day was started, the dose of vitamin D was increased to 14,000 IU per week, and ramipril 5 mg per day was prescribed due to secondary hypertension. In addition, given the severity of osteoporosis, it was decided to replace previously prescribed alendronate with zoledronic acid.

Magnetic resonance imaging of the upper abdomen was performed on 06/19/2021, which demonstrated lobulated nodular thickening in the left adrenal gland with areas of decreased signal intensity in the T1 out-phase sequence, denoting the presence of fat, and homogeneous enhancement using contrast, measuring approximately 1.7 × 1.5 × 1.3 cm, suggestive of an adenoma. There was also a small nodular thickening in the lateral arm of the right adrenal, measuring approximately 0.8 × 0.6 cm, which was difficult to characterize due to its small dimensions and nonspecific appearance.

PPNAD or carcinoma became an important etiological hypothesis for the case described when comparing the epidemiology in a young man and the clinical-laboratory-imaging findings of the differential diagnoses. According to a dialog with the patient and family, the group of experts opted for unilateral glandular surgical resection on the left side (11/11/2021), where more significant changes were visualized, as there was a possibility of malignancy in a young patient and to avoid a definitive adrenal insufficiency condition because of bilateral adrenalectomy. This would first allow the analysis of the material and follow-up of the evolution of the condition with the permanence of the contralateral gland.

In the macroscopic analysis of the adrenalectomy specimen, adrenal tissue weighing 20 g and measuring 9.3 × 5.5 × 2.0 cm was described, completely surrounded by adipose tissue. The gland has a multinodular surface and varies between 0.2 and 1.6 cm in thickness, showing a cortex of 0.1 cm in thickness and a medulla of 1.5 cm in thickness (Fig. 4).

Fig. 4

figure 4

Left adrenal

The microscopic analysis described the expansion of the zona fasciculate, with the formation of multiple nonencapsulated nodules composed of polygonal cells with ample and eosinophilic cytoplasm and frequent depletion of intracytoplasmic lipid content. No areas of necrosis or mitotic activity were observed. The histopathological picture is suggestive of cortical pigmented micronodular hyperplasia of the adrenal gland.

For the final etiological definition and an indication of contralateral adrenalectomy, which could be unnecessary and would avoid chronic corticosteroid therapy, or else, it would be necessary to protect the patient from future complications with the maintenance of the disease in the right adrenal gland, it would be essential to search for mutations in the PRKAR1A, PDE11A, PDE8B and PRKACA genes [15]; however, such genetic analysis is not yet widely available, and the impossibility of carrying it out at the local level did not allow a complete conclusion of the case.

Discussion

Through the clinical picture presented and the research of several secondary causes for osteoporosis, it was possible to arrive at the diagnosis of Cushing syndrome [6]. There was symptomatic independent ACTH hypercortisolism, manifested by typical phenotypic changes, severe secondary osteoporosis, and arterial hypertension in a young patient.

The diagnosis of Cushing’s syndrome is always challenging, given the presence of confounding factors such as the following:

  • Physiological states of hypercortisolism—pseudo Cushing (strenuous exercise, pregnancy, uncontrolled diabetes, sleep apnea, chronic pain, alcohol withdrawal, psychiatric disorders, stress, obesity, glucocorticoid resistance syndromes);
  • Cyclic or mild—subclinical Cushing’s pictures;
  • Frequent and, even unknown, short- and long-term use of corticosteroids under different presentations;
  • Increase in the general population incidence of diabetes and obesity;
  • Screening tests with singularities for collection and individualized for different patient profiles.

It is important to note that the basal morning cortisol measurement is not the ideal test to assess hypercortisolism and is better applied to the assessment of adrenal insufficiency. However, the hypercortisolism of the case was unequivocal, and this test was also shown to be altered several times. As no test is 100% accurate, the current guidelines suggest the use of at least two first-line functional tests that focus on different aspects of the pathophysiology of the hypothalamic‒pituitary‒adrenal axis to confirm the hypercortisolism state: 24-hours cortisol, nocturnal salivary cortisol, morning serum cortisol after suppression with 1 mg of dexamethasone or after Liddle 1. Given that night-time salivary cortisol would require hospitalization, the other suggested tests were chosen, which are easier to perform in this context [7, 8].

Subsequently, tests were performed to determine the cause of hypercortisolism, such as serum ACTH levels and adrenal CT. The suppressed ACTH denoted the independence of its action. CT showed bilateral adrenal nodules with more severe features: solid lesion, attenuation > 10 UI on noncontrast images, and contrast washout speed < 60% in 10 minutes. In this case, it is essential to make a broad clinical decision and dialog with the patient to weigh and understand the risks and benefits of surgical treatment [9].

Among the main diagnostic hypotheses for the differential diagnosis of bilateral adrenal hyperplasia are primary bilateral macronodular adrenal hyperplasia, McCune–Albright syndrome (MAS) and bilateral primary pigmented nodular hyperplasia (PPNAD) isolated or associated with Carney’s complex. Another possibility would be bilateral adrenocorticotropic hormone (ACTH)-dependent macronodular hyperplasia secondary to long-term adrenal stimulation in patients with Cushing’s disease (ACTH-secreting pituitary tumor) or ectopic ACTH production, but the present case did not present with ACTH elevation.

Primary macronodular adrenal hyperplasia (nodules > 1 cm) predominates in women aged 50–60 years and may also be detected in early childhood (before 5 years) in the context of McCune–Albright syndrome. Most cases are considered sporadic; however, there are now several reports of familial cases whose presentation suggests autosomal dominant transmission. Several pathogenic molecular causes were identified in the table, indicating that it is a heterogeneous disease [10]. The pathophysiology occurs through the expression of anomalous ectopic hormone receptors or amplified eutopic receptors in the adrenals. It usually manifests in an insidious and subclinical way, with cortisol secretion mediated through receptors for gastric inhibitory peptide (GIP), vasopressin (ADH), catecholamines, interleukin 1 (IL-1), leptin, luteinizing hormone (LH), serotonin or others. Nodular development is not always synchronous or multiple; thus, hypercortisolism only manifests when there is a considerable increase in the number of adrenocortical cells, with severe steroidogenesis observed by cortisoluria greater than 3 times the upper limit of normal. Patients with mild Cushing’s syndrome should undergo screening protocols to identify aberrant receptors, as this may alter the therapeutic strategy. If there is evidence of abnormal receptors, treatment with beta-blockers is suggested for patients with beta-adrenergic receptors or with gonadotropin-releasing hormone (GnRH) agonists (and sex steroid replacement) for patients with LH/hCG receptors. In patients in whom aberrant hormone receptors are not present or for whom no specific pharmacological blockade is available or effective, the definitive treatment is bilateral adrenalectomy, which is known to make the patient dependent on chronic corticosteroid therapy [11]. Studies have shown the effectiveness of unilateral surgery in the medium and long term, opting for the resection of the adrenal gland of greater volume and nodularity by CT, regardless of the values obtained by catheterization of adrenal veins, but with the possibility of persistence or recurrence in the contralateral gland. Another possibility would be total unilateral adrenalectomy associated with subtotal contralateral adrenalectomy [12].

In McCune–Albright syndrome (MAS), there are activating mutations in the G-protein GNAS1 gene, generating autonomic hyperfunction of several tissues, endocrine or not, and there may be, for example, a constant stimulus similar to ACTH on the adrenal gland. In this case, pituitary levels of ACTH are suppressed, and adrenal adenomas with Cushing’s syndrome appear. Hypercortisolism may occur as an isolated manifestation of the syndrome or be associated with the triad composed of polyostotic fibrous dysplasia, café au lait spots with irregular borders and gonadal hyperfunction with peripheral precocious puberty. The natural history of Cushing’s syndrome in McCune-Albright syndrome (MAS) is heterogeneous, with some children evolving with spontaneous resolution of hypercortisolism, while others have a more severe condition, eventually requiring bilateral adrenalectomy [13].

PPNAD predominates in females, in people younger than 30 years, multiple and small (< 6 mm) bilateral pigmented nodules (surrounded by atrophied cortex), which can reach 1.5 cm in adulthood, with family genetic inheritance (66%) or sporadic inheritance (33%), and as part of the Carney complex reported in 40% of cases. In 70% of cases, inactivating mutations are identified in the PKA regulatory 1-alpha subunit (PRKAR1A), a tumor suppressor gene [14]. Osteoporosis is often associated with this condition [15]. One test that can distinguish patients with PPNAD from other primary adrenocortical lesions is cortisoluria after sequential suppression with low- and high-dose dexamethasone. In contrast to most patients with primary adrenocortical disease, who demonstrate no change in urinary cortisol, 70% of PPNAD patients have a paradoxical increase in urinary cortisol excretion [16]. The treatment of choice for PPNAD is bilateral adrenalectomy due to the high recurrence rate for primary adrenal disease [17].

Carney complex is a multiple neoplastic syndrome with autosomal dominant transmission, characterized by freckle-like cutaneous hyperpigmentation (lentiginosis), endocrine tumors [(PPNAD), testicular and/or thyroid tumors and acromegaly] and nonendocrine tumors, including cutaneous, cardiac, mammary, and osteochondral myxomas, among others. In the above case, the transthoracic echocardiogram of the patient on 03/18/2021 showed cavities of normal dimensions, preserved systolic and diastolic functions, no valve changes and no lentiginous skin areas and blue nevi, making the diagnosis of the syndrome less likely. The definitive diagnosis of Carney requires two or more main manifestations. Several related clinical components may suggest the diagnosis but not define it. The diagnosis can also be made if a key criterion is present and a first-degree relative has Carney or an inactivating mutation of the gene encoding PRKAR1A [18].

The adenoma is usually small in size (< 3 cm), similar to the nodules in this case; however, it is usually unilateral, with an insidious and mild evolution, especially in adult women over 35 years of age, producing only 1 steroid class. Carcinomas are usually large (> 6 cm), and only 10% are bilateral. They should be suspected mainly when the tumor presents with hypercortisolism associated with hyperandrogenism. They have a bimodal age distribution, with peaks in childhood and adolescence, as well as at the end of life [3].

Conclusion

Early identification of Cushing’s syndrome, with measures based on the assessment of risks and benefits, remains the best way to prevent progression and reduce morbidity [2]. After 6 months of drug inhibition of steroidogenesis, blood pressure control and anti-osteoporotic therapy, the objective was to minimize the levels and deleterious metabolic effects of hypercortisolism, which could also harm the surgical procedure in the short and long term through infections, dehiscence, nonimmediate bed mobilization and cardiovascular events. Unilateral adrenalectomy was chosen, given the possibility of malignancy in a young patient and to avoid definitive surgical adrenal insufficiency if the adrenalectomy was bilateral. Despite the unavailability of genetic analysis for a precise etiological definition, it is possible to take efficient measures to avoid unnecessary consequences or damage.

Availability of data and materials

All data generated or analysed during this study are included in this published article [and its Additional file 1]. The datasets generated and/or analysed during the current study are available in the link https://ufjfedubr-my.sharepoint.com/:v:/g/personal/barbara_reis_ufjf_edu_br/EVpIR005sPZGlQvMJhIwSaUB0Hig4KOjhkG4D4cMggUwHA?e=Dk8tng.

Abbreviations

ACTH:
Adrenocorticotropic hormone
PPNAD:
Bilateral primary pigmented nodular hyperplasia
DXA:
Dual energy X-ray absorptiometry
GIP:
Gastric inhibitory peptide
GnRH:
Gonadotropin-releasing hormone
IL-1:
Interleukin 1
BMD:
Low bone mineral density
LH:
Luteinizing hormone
MAS:
McCune–Albright syndrome
PRKAR1A:
PKA regulatory 1-alpha subunit
ADH:
Vasopressin

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Acknowledgements

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Author information

Authors and Affiliations

  1. Serviço de Endocrinologia, Hospital Universitário da Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil

    Bárbara Oliveira Reis, Christianne Toledo Sousa Leal, Danielle Guedes Andrade Ezequiel, Ana Carmen dos Santos Ribeiro Simões Juliano, Flávia Lopes de Macedo Veloso, Leila Marcia da Silva, Lize Vargas Ferreira, Mariana Ferreira & Gabriel Zeferino De Oliveira Souza

Contributions

All the authors contributed to the conception and design of the work and have approved the submitted version. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Bárbara Oliveira Reis.

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Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

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The authors declare that they have no competing interests.

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Supplementary Information

Additional file 1. Surgical removal of adrenal gland.

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Catastrophic ACTH-secreting Pheochromocytoma

Posted on June 6, 2023 by MaryO

Abstract

Summary

Cushing’s syndrome due to ectopic adrenocorticotropic hormone (ACTH) secretion (EAS) by a pheochromocytoma is a challenging condition. A woman with hypertension and an anamnestic report of a ‘non-secreting’ left adrenal mass developed uncontrolled blood pressure (BP), hyperglycaemia and severe hypokalaemia. ACTH-dependent severe hypercortisolism was ascertained in the absence of Cushingoid features, and a psycho-organic syndrome developed. Brain imaging revealed a splenial lesion of the corpus callosum and a pituitary microadenoma. The adrenal mass displayed high uptake on both 18F-FDG PET/CT and 68Ga-DOTATOC PET/CT; urinary metanephrine levels were greatly increased. The combination of antihypertensive drugs, high-dose potassium infusion, insulin and steroidogenesis inhibitor normalized BP, metabolic parameters and cortisol levels; laparoscopic left adrenalectomy under intravenous hydrocortisone infusion was performed. On combined histology and immunohistochemistry, an ACTH-secreting pheochromocytoma was diagnosed. The patient’s clinical condition improved and remission of both hypercortisolism and catecholamine hypersecretion ensued. Brain magnetic resonance imaging showed a reduction of the splenial lesion. Off-therapy BP and metabolic parameters remained normal. The patient was discharged on cortisone replacement therapy for post-surgical hypocortisolism. EAS due to pheochromocytoma displays multifaceted clinical features and requires prompt diagnosis and multidisciplinary management in order to overcome the related severe clinical derangements.

Learning points

  • A small but significant number of cases of adrenocorticotropic hormone (ACTH)-dependent Cushing’s syndrome are caused by ectopic ACTH secretion by neuroendocrine tumours, which is usually associated with severe hypercortisolism causing severe clinical and metabolic derangements.
  • Ectopic ACTH secretion by a pheochromocytoma is exceedingly rare but can be life-threatening, owing to the simultaneous excess of both cortisol and catecholamines.
  • The combination of biochemical and hormonal testing and imaging procedures is mandatory for the diagnosis of ectopic ACTH secretion, and in the presence of an adrenal mass, the possibility of an ACTH-secreting pheochromocytoma should be taken into account.
  • Immediate-acting steroidogenesis inhibitors are required for the treatment of hypercortisolism, and catecholamine excess should also be appropriately managed before surgical removal of the tumour.
  • A multidisciplinary approach is required for the treatment of this challenging entity.
Keywords: Adult; Female; White; Italy; Adrenal; Pituitary; Unique/unexpected symptoms or presentations of a disease; May; 2023

Background

Cushing’s syndrome (CS) is a rare endocrine disease characterized by high levels of glucocorticoids; it increases morbidity and mortality due to cardiovascular and infectious diseases (1, 2, 3).

To diagnose CS, adrenocorticotropic hormone (ACTH)-dependent disease must be distinguished from ACTH-independent disease, and pituitary ACTH production from ectopic production. About 20% of ACTH-dependent cases arise from ectopic ACTH secretion (EAS) (2, 3, 4). EAS is most often due to aberrant ACTH production by small-cell lung carcinoma or neuroendocrine tumours originating in the lungs or gastrointestinal tract; this, in turn, strongly increases cortisol production by the adrenal glands (3, 4, 5).

Since the first-line treatment of EAS is the surgical removal of the ectopic ACTH-secreting tumour, its prompt and accurate localization is crucial.

Rapid cortisol reduction by means of immediate-acting steroidogenesis inhibitors (4) is mandatory in order to treat the related endocrine, metabolic and electrolytic derangements. EAS by a pheochromocytoma is exceedingly rare and can be life-threatening.

We describe the case of a woman with hypertension and a known ‘non-secreting’ left adrenal mass, who manifested uncontrolled blood pressure (BP), hyperglycaemia, hypokalaemia and psycho-organic syndrome associated with damage of the splenium of the corpus callosum. These findings were eventually seen to be related to an ACTH-secreting left pheochromocytoma, which was ascertained by hormonal evaluation and morphological and functional imaging assessment and confirmed by histopathology/immunostaining. Hormonal hypersecretion resolved after adrenalectomy and metabolic derangements normalized.

Case presentation

A 72-year-old woman with hypertension was taken to the emergency department because of increased BP (200/100 mm Hg). High BP (190/100 mmHg) was confirmed, whereas oxygen saturation (98%), heart rate (84 bpm) and lung and abdomen examination were normal. Electrocardiogram and chest x-ray were unremarkable. Captopril 50 mg orally, followed by intramuscular clonidine, normalized BP.

The patient looked thin and reported significant weight loss (10 kg) over the previous 6 months; she was on antihypertensive therapy with bisoprolol 5 mg/day and irbesartan 150 mg/day, and ezetimibe 10 mg/day for dyslipidaemia. The patient’s records included a previous diagnosis in another hospital of normofunctioning multinodular goitre and a 2.5 cm-left solid inhomogeneous adrenal mass with well-defined margins, which was found on CT performed 6 years earlier during the work-up for hypertension. On the basis of hormonal data and absent uptake on 123I metaiodobenzylguanidine scintigraphy, the adrenal lesion had been deemed to be non-functioning and follow-up had been advised. Unfortunately, only initial cortisol (15.7 μg/dL) and 24-h urine-free cortisol (UFC) levels (32.5 μg/24 h) were retrievable; both proved normal.

Investigations

Blood chemistry showed neutrophilic leucocytosis, hyperglycaemia with increased glycated haemoglobin, severe hypokalaemia and metabolic alkalosis (Table 1). Potassium infusion (50 mEq in 500 mL saline/24 h) was rapidly started, together with a subcutaneous rapid-acting insulin analogue and prophylactic enoxaparin. The patient experienced mental confusion, hallucinations and restlessness; non-enhanced computed tomography (CT) of the brain revealed a hypodense area of the splenium of the corpus callosum, possibly due to metabolic damage (Fig. 1A).

Figure 1View Full Size
Figure 1

Non-enhanced CT showing a hypodense area of the splenium of the corpus callosum (arrows), without mass effect (A, axial view). Contrast-enhanced MR image showing a hypointense pituitary lesion (arrow) which enhances more slowly than normal pituitary parenchyma, deemed suspicious for microadenoma (B, coronal view). FLAIR MR image showing hyperintense signal of the splenium of the corpus callosum (asterisk), which partially extended to the crux of the left fornix (arrow) (C, axial view). As the lesion showed no restricted diffusion on DWI (D, axial view), an ischaemic lesion was excluded. A progressive reduction in the extension of the hyperintense signal in the splenium of the corpus callosum (arrowheads) and in the crux of the left fornix (arrows) was observed on FLAIR MR images (2 months (E); 3 months (F); axial view). CT, computed tomography; DWI, diffusion-weighted imaging; FLAIR, fluid-attenuated inversion recovery; MR, magnetic resonance.

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 2; 10.1530/EDM-22-0308

Table 1Hormonal and biochemical evaluation of patient throughout hospitalization and follow-up.

Normal range On hospital admission After surgery
10 days 2 months 3 months 6 months 9 months 12 months 16 months
ACTH (pg/mL) 9–52 551 7 37 50 29.5 26 40.9 52
Morning cortisol† (µg/dL) 7–19.2 63.4 14 5.1 3.5 3.8 4.2 7.2 12.8
After 1 mg overnight dexamethasone
 ACTH 583
 Cortisol 60
DHEAS (µg/dL) 9.4–246 201
24-h urinalysis (µg/24 h)
 Adrenaline 0–14.9 95.5
 Noradrenaline 0–66 1133
 Metanephrine 74–297 1927
 Normetanephrine 105–354 1133
Chromogranin A 0–108 290
Renin (supine) (µU/mL) 2.4–29 3.9 14.6
Aldosterone (supine) (ng/dL) 3–15 3.4 12.5
LH (mIU/mL)* > 10 0.3 65.8
FSH (mIU/mL)* > 25 1.9 116
PRL (ng/mL) 3–24 13.7
FT4 (ng/dL) 0.9–1.7 1.1 1.2
FT3 (pg/mL) 1.8–4.6 1.1 2.7
TSH (µU/mL) 0.27–4.2 0.23 1.3
PTH (pg/mL) 15–65 166
Calcium (mg/dL) 8.2–10.2 8.2
Calcitonin (pg/mL) 0–10 1
Glycaemia (mg/dL) 60–110 212 69 73 83
Potassium (mEq/L) 3.5–5 2.4 3.3 3.9 4.2 3.7 5 4.4 3.9
Leucocytes (K/µL) 4.0–9.3 15.13
HbA1c (mmol/mol) 20–42 55 30
HCO3− (mEq/L) 22–26 41.8

*For menopausal age; †07:00–10:00 h.

 

The patient was transferred to the internal medicine ward. Although potassium infusion was increased to 120 mEq/day, serum levels did not normalize; a mineralocorticoid receptor antagonist (potassium canreonate) was therefore introduced, but the effect was partial. In order to control BP, the irbersartan dose was increased (300 mg/day) and amlodipine (10 mg/day) was added.

The combination of severe hypertension, newly occurring diabetes and resistant hypokalaemia prompted us to hypothesize a common endocrine aetiology.

A thorough hormonal array showed very high ACTH and cortisol levels, whereas supine renin and aldosterone levels were in the low-normal range (Table 1). Since our patient proved repeatedly non-compliant with 24-h urine collection, UFC could not be measured.

After an overnight 1 mg dexamethasone suppression test, cortisol levels remained unchanged, whereas ACTH levels slightly increased (Table 1). Notably, the patient showed no Cushingoid features. Gonadotropin levels were inappropriately low for the patient’s age; FT4 levels were normal, whereas FT3 and thyroid-stimulating hormone (TSH) levels were reduced and calcitonin levels were normal (Table 1). HbA1c levels were increased (Table 1).

Finally, secondary hyperparathyroidism, associated with low-normal calcium levels and reduced vitamin D levels, was found (Table 1).

Brain contrast-enhanced magnetic resonance (MR) imaging revealed a 5-mm median posterior pituitary microadenoma (Fig. 1B) and a hyperintense lesion of the splenium of the corpus callosum (Fig. 1C). Diffusion-weighted MR images of the lesion showed no restricted diffusion (Fig. 1D), thus excluding an ischaemic origin. Petrosal venous sampling for ACTH determination at baseline and after CRH stimulation was excluded, as it was deemed a high-risk procedure, given the patient’s poor condition.

Since the ACTH and cortisol levels were greatly increased and were associated with severe hypokalaemia, EAS was hypothesized; total-body contrast-enhanced CT revealed the left adrenal mass (3 cm), which showed regular margins and heterogeneous enhancement (Fig. 2A and B) and measured 25 Hounsfield units. There was no evidence of adrenal hyperplasia in the contralateral adrenal gland. The adrenal mass showed intense tracer uptake on both 18F-FDG PET/CT (Fig. 2C and D), suggestive of adrenal malignancy or functioning tumour, and 68Ga-DOTATOC PET/CT (Fig. 3), which is characteristic of a neuroendocrine lesion. No other sites of suspicious tracer uptake were detected.

Figure 2View Full Size
Figure 2

Contrast-enhanced abdominal computed tomography showing a 3-cm left adrenal mass (arrow) with well-defined margins and inhomogeneus enhancement, deemed compatible with an adenoma (A, coronal view; B, axial view). The adrenal mass showed high uptake (SUV max: 7.3) on 18F-FDG PET/CT (C, coronal view; D, axial view).

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 2; 10.1530/EDM-22-0308

Figure 3View Full Size
Figure 3

The left adrenal mass displaying very high uptake (SUV max: 40) on 68Ga-DOTATOC PET/CT (arrow, axial view).

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 2; 10.1530/EDM-22-0308

 

Bisoprolol was withdrawn, and 24-h urinary catecholamine, metanephrine and normetanephrine levels proved significantly increased, as were chromogranin A levels (Table 1). In sum, an ACTH-secreting pheochromocytoma was suspected and the pituitary microadenoma was deemed a likely incidental finding.

The patient’s mental state worsened, fluctuating from sopor to restlessness, which required parenteral neuroleptics and restraint. An electroencephalogram revealed a specific slowdown of cerebral electrical activity. Following rachicentesis, the cerebrospinal fluid showed pleocytosis (lympho-monocytosis), whereas a culture test and polymerase chain reaction for common neurotropic agents were negative. The neurologist hypothesized a psycho-organic syndrome secondary to severe metabolic derangement. Intravenous ampicillin, acyclovir and B vitamins were empirically started. The patient was transferred to the subintensive unit, where a nasogastric tube and central venous catheter were inserted, and enteral nutrition was started.

Treatment

Ketoconazole was started at a dosage of 200 mg twice daily; both cortisol and ACTH levels significantly decreased over a few days (Fig. 4), with a progressive decrease in glucose levels and normalization of potassium levels and BP on therapy. Subsequently, ketoconazole was titrated to 600 mg/day owing to a new increase in cortisol levels, which eventually normalized (Fig. 4). Of note, ACTH levels partially decreased on ketoconazole treatment (Fig. 4).

Figure 4View Full Size
Figure 4

ACTH and cortisol levels throughout the patient’s hospitalization and follow-up.

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 2; 10.1530/EDM-22-0308

 

Doxazosin 2 mg/day was added and the patient’s systolic BP blood settled at around 100 mm Hg; after a few days, bisoprolol was restarted. Contrast-enhanced MR showed a partial reduction of the hyperintense splenial lesion (Fig. 1E). Despite the severe clinical condition and the high risks of adrenal surgery, the patient’s relatives strongly requested the procedure and laparoscopic left adrenalectomy was planned. Alpha-blocker and fluid infusion were continued, ketoconazole was withdrawn the day before surgery, and a 100 mg IV bolus of hydrocortisone was administered just before the operation, followed by 200 mg/day, at first in continuous infusion, then as a 100 mg bolus every 8 h. After the removal of the left adrenal mass, noradrenaline infusion was required, owing to the occurrence of severe hypotension.

Outcome and follow-up

Pathology revealed a 2.5 cm reddish-brown encapsulated tumour, which was compatible with pheochromocytoma (Fig. 5A and B); ACTH immunostaining was positive in about 30% of tumour cells (Fig. 5C). This confirmed the diagnostic hypothesis of an ACTH-secreting pheochromocytoma. The tumour was stained for Chromogranin A (Fig. 5D). There were no signs of adrenal cortex hyperplasia in the resected gland. Thorough germinal genetic testing, comprising the commonest pheochromocytoma/paraganglioma genes: CDKN1B, KIF1B, MEN1, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2 and TMEM127, was negative.

Figure 5View Full Size
Figure 5

Histological images of adrenal pheochromocytoma: the tumour is composed of well-defined nests of cells (‘zellballen’) (A; haematoxylin-eosin stain (HE), ×20) with pleomorphic nuclei with prominent nucleoli, basophilic or granular amphophilic cytoplasm (B; HE, ×40). The mitotic index was low: 1 mitosis per 30 high-power fields, and Ki-67 was 1%. On immunohistochemistry, cytoplasmatic ACTH staining was found in about 30% of tumour cells (C; ×20), whereas most tumour cells were stained for chromogranin A (D; ×20).

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 2; 10.1530/EDM-22-0308

 

One week after surgery ACTH levels had dropped to a low-normal value: 7 pg/mL, and cortisol levels (before morning hydrocortisone bolus administration) were normal: 14 µg/dL (Fig. 4). The patient’s clinical status slowly improved and the nasogastric tube was removed; intravenous hydrocortisone was carefully tapered until withdrawal and high-dose oral cortisone acetate (62.5 mg/day) was started. This dose was initially required since BP remained low (systolic: 90 mm Hg); thereafter, cortisone was reduced to 37.5 mg/day. Plasma cortisol levels before morning cortisone administration were reduced (Fig. 4). A new MR of the brain showed a further partial reduction of the splenial lesion (Fig. 1F). The patient was discharged with normal off-therapy BP and metabolic parameters.

During follow-up, she fully recovered, and BP and metabolic parameters remained normal. Gonadotropin levels became adequate for the patient’s age, and TSH and renin/aldosterone levels normalized (Table 1). Hypoadrenalism, however, persisted for more than 1 year; as the last hormonal evaluation, 16 months after surgery, showed normal baseline cortisol levels, the cortisone dose was tapered (12.5 mg/day) and further hormonal examination was scheduled (Table 1). ACTH and cortisol levels throughout the patient’s hospitalization and follow-up are shown in Fig. 4.

Discussion

The diagnosis of EAS is challenging and requires two steps: confirmation of increased ACTH and cortisol levels and anatomic distinction from pituitary sources of ACTH overproduction. Besides metabolic derangements (hyperglycaemia, hypertension), EAS-related severe hypercortisolism may cause profound hypokalaemia (3, 4, 5).

In our patient, the combination of worsening hypertension, newly occurring diabetes and resistant hypokalaemia raised the suspicion of a common endocrine cause.

ACTH-dependent severe hypercortisolism was ascertained, and subsequent brain MR revealed a pituitary microadenoma.

The diagnosis of CS requires the combination of two abnormal test results: 24-h UFC, midnight salivary cortisol and/or abnormal 1 mg dexamethasone suppression testing (2, 6). ACTH evaluation (low/normal-high) is fundamental to tailoring the imaging technique.

The very high cortisol levels found in our patient were unchanged after overnight dexamethasone testing, whereas UFC could not be assessed owing to the lack of compliance with urine collection. The accuracy of the UFC assays, however, may be impaired by cortisol precursors and metabolites. Salivary cortisol assessment was not performed since the specific assay is not available in our hospital.

The combination of ACTH-dependent severe hypercortisolism and hypokalaemia prompted us to suspect EAS. The differential diagnosis between pituitary and ectopic ACTH-dependent CS involves high-dose (8 mg) dexamethasone suppression testing, which has relatively low diagnostic accuracy (6). Owing to the patient’s very high cortisol levels and severe hypokalaemia, this testing was not performed, on account of the risks of administering corticosteroids in a patient already exposed to excessive levels (6). Furthermore, owing to the increase in ACTH levels observed after overnight dexamethasone testing, we postulated the possible occurrence of glucocorticoid-driven positive feedback on ACTH secretion, which has been described in EAS, including cases of pheochromocytoma (7).

Finally, in the case of EAS suspected of being caused by pheochromocytoma, we do not recommend performing high-dose dexamethasone suppression testing, owing to the risk of triggering a catecholaminergic crisis (8).

The dynamic tests commonly used to distinguish patients with EAS from those with Cushing’s disease are the CRH stimulation test and the desmopressin stimulation test, either alone or in combination with CRH testing (6). Owing to the rapid worsening of our patient’s condition, dynamic testing was not done; however, the clinical picture and hormonal/biochemical data were suggestive of EAS.

EAS is mainly (45–50%) due to neuroendocrine tumours, mostly of the lung (small-cell lung cancer and bronchial tumours), thymus or gastrointestinal tract; however, up to 20% of ACTH-secreting tumours remain occult (3, 4, 5).

ACTH-secreting pheochromocytomas are responsible for about 5% of cases of EAS (3, 4, 9, 10). Indeed, this rate ranges widely, from 2.5% (11) to 15% (12), according to the different case series. Patients with EAS due to pheochromocytoma present with severe CS, overt diabetes mellitus, hypertension and hypokalaemia (3); symptoms of catecholamine excess may be unapparent (3), making the diagnosis more challenging.

A recent review of 99 patients with ACTH- and/or CRH-secreting pheochromocytomas found that the vast majority displayed a Cushingoid phenotype (10); by contrast, another review of 24 patients reported that typical Cushingoid features were observed in only 30% of patients, whereas weight loss was a prevalent clinical finding (13). We hypothesized that the significant weight loss reported by our patient was largely due to the hypermetabolic state induced by catecholamines, which directly reduce visceral and subcutaneous fat, as recently reported (14).

Our patient showed no classic stigmata of CS, owing to the rapid onset of severe hypercortisolism (10, 13), whereas she had worsening hypertension and newly occurring diabetes mellitus, which were related to both cortisol and catecholamine hypersecretion; hypokalaemia was deemed to be secondary to severe hypercortisolism. Indeed, greatly increased cortisol levels act on the mineralocorticoid receptors of the distal tubule after saturating 11β-hydroxysteroid dehydrogenase type 2, leading to hypokalaemia (4). Consequently, hypokalaemia is much more common (74–95% of patients) in EAS than in classic Cushing’s disease (10%) (3, 4, 10). This apparent mineralocorticoid excess suppresses renin and aldosterone secretion, as was ascertained in our patient.

In this setting, the most effective way to manage hypokalaemia is to treat the hypercortisolism itself by administering immediate-acting steroidogenesis inhibitors, combined with potassium infusion and a mineralocorticoid receptor-antagonist (e.g. spironolactone) at an appropriate dosage (100–300 mg/day) (4).

In ACTH-secreting pheochromocytoma, cortisol hypersecretion potentiates catecholamine-induced hypertension by stimulating the phenol-etholamine-N-methyl–transferase enzyme, which transforms noradrenaline to adrenaline (4). Indeed, in our patient, the significant ketoconazole-induced reduction in cortisol secretion led to satisfactory BP control on antihypertensive drugs. After the biochemical diagnosis of pheochromocytoma, a selective alpha-blocker was added, and after a few days, a beta-blocker was restarted in order to control reflex tachycardia (15).

Our patient had greatly increased ACTH levels (>500 pg/mL) associated with very high cortisol levels (>60 µg/dL), which, together with the finding of hypokalaemia, prompted us to hypothesize EAS. With regard to these findings, ACTH levels are usually higher (>200 pg/mL) in patients with EAS than in those with CS due to a pituitary adenoma; however, considerable overlapping occurs (3, 11, 16). Most patients with ACTH-secreting pheochromocytomas in those series had ACTH levels >300 pg/mL, and a few had normal ACTH levels (9), thus complicating the diagnosis. In addition, patients with EAS usually have higher cortisol levels than those with ACTH-secreting adenomas (3, 11).

In our patient, the left adrenal mass was deemed the culprit of EAS, and owing to very high urinary metanephrine levels, a pheochromocytoma was suspected.

It can be assumed that the adrenal tumour, which was anamnestically reported as ‘non-secreting’, but on which only part of the initial hormonal data were available, was actually a pheochromocytoma at the time of the first diagnosis but displayed a silent clinical and hormonal behaviour. The mass subsequently showed significant uptake on both 18F-FDG PET/CT and 68Ga-DOTATOC PET/CT (4, 5). It is claimed that 68Ga-DOTATOC PET/CT provides a high grade (90%) of sensitivity and specificity in the diagnosis of tumours that cause EAS (4, 5); nevertheless, a recent systematic review reported much lower sensitivity (64%), which increased to 76% in histologically confirmed cases (17).

In patients with EAS, immediate-acting steroidogenesis inhibitors are required in order to achieve prompt control of severe hypercortisolism (4). Ketoconazole is one of the drugs of choice since it inhibits adrenal steroidogenesis at several steps. In our patient, ketoconazole rapidly reduced cortisol levels to normal values, without causing hepatic toxicity (4). Moreover, ketoconazole proved effective at a moderate dosage (600 mg/day), which falls within the mean literature range (18, 19). However, dosages up to 1200–1600 mg/day are sometimes required in severe cases (usually EAS) (18, 19). Speculatively, our results might reflect an enhanced inhibitory action of ketoconazole at the adrenal level, which was able to override the strong ectopic ACTH stimulation.

In addition, the finding that, following cortisol reduction, ACTH levels paradoxically decreased suggests an additive and direct effect of the drug. This effect has been observed in a few patients with EAS (20) and is supported by in vitro studies showing a direct anti-proliferative and pro-apoptotic effect of ketoconazole on ectopic ACTH secretion by tumours (21). Finally, the reduction in ACTH levels during treatment with steroidogenesis inhibitors prompts us to postulate the presence of glucocorticoid-driven positive feedback on ACTH secretion, as already described in neuroendocrine tumours (7, 20, 21). The coexistence of EAS and ACTH-producing pituitary adenoma is very rare but must be taken into account. In our case, we deemed the pituitary mass found on MR to be a non-secreting microadenoma. This hypothesis was strengthened by the finding that, following exeresis of the ACTH-secreting pheochromocytoma, ACTH normalized, hypercortisolism vanished and pituitary function recovered. These findings suggest that: (i) altered pituitary function at the baseline was secondary to the inhibitory effect of hypercortisolism; (ii) the excessive production of cortisol was driven by ACTH overproduction outside the pituitary gland, specifically within the adrenal gland tumour.

In our patient, a few days after surgery, morning cortisol levels before hydrocortisone bolus administration were ‘normal’. Owing to both the half-life of hydrocortisone (8–12 h) and the supraphysiological dosage used, it is likely that a residual part of the drug, which cross-reacts in the cortisol assay, was still circulating at the time of blood collection, thus resulting in ‘normal’ cortisol values. Following the switch to oral cortisone, cortisol levels before therapy were low, thus confirming post-surgical hypocortisolism. Hypocortisolism remained throughout the first year after surgery, and glucocorticoid therapy was continued. Sixteen months after surgery, baseline cortisol levels returned to the normal range; cortisone therapy was therefore tapered and a further hormonal check was scheduled. Assessment of the cortisol response to ACTH stimulation testing would be helpful in order to check the resumption of the residual adrenal function.

A peculiar aspect of our case was the occurrence of a psycho-organic syndrome together with the finding of a splenial lesion on brain imaging, which was deemed secondary to metabolic injury. Indeed, the increased cortisol levels present in patients with Cushing’s disease are detrimental to the white matter of the brain, including the corpus collosum, causing subsequent clinical derangements (22).

Besides the direct effects of hypercortisolism, the splenial damage was also probably due to long-standing hypertension, worsened by newly occurring catecholamine hypersecretion and diabetes. Together with the normalization of cortisol and glycaemic levels, and of BP, a partial reduction in the splenial damage was observed on two subsequent MR examinations, and the patient’s neurological condition slowly improved until she fully recovered.

In our patient, thorough germinal genetic testing for the commonest pheochromocytoma/paraganglioma (PPGL) genes proved negative. Since approximately 40% of these tumours have germline mutations, genetic testing is recommended regardless of the patient’s age and family history. In the absence of syndromic, familial or metastatic presentation, the selection of genes for testing may be guided by the tumour location and biochemical phenotype.

Alterations of the PPGL genes can be divided into two groups: 10 genes (RET, VHL, NF1, SDHD, SDHAF2, SDHC, SDHB, SDHA, TMEM127 and MAX) that have well-defined genotype–phenotype correlations, thus allowing to tailor imaging procedures and medical management, and a group of other emerging genes, which lack established genotype–phenotype associations; for patients in whom mutations of genes belonging to this second group are detected, and hence hereditary predisposition is established, only general medical surveillance and family screening can be planned (23, 24).

In conclusion, our case highlights the importance of investigating patients with hypertension and metabolic derangements such as diabetes and hypokalaemia, since these findings may be a sign of newly occurring EAS, which, in rare cases, may be due to an ACTH-secreting pheochromocytoma. Since the additive effect of cortisol and catecholamine can cause dramatic clinical consequences, the possibility of an ACTH-secreting pheochromocytoma should be taken into account in the presence of an adrenal mass. EAS must be considered an endocrine emergency requiring urgent multi-specialist treatment. Surgery, whenever possible, is usually curative, and anatomic brain damage, as ascertained in our patient, may be at least partially reversible.

Declaration of interest

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding

This study did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector. The study was approved by the Local Ethics Committee (no: 732/2022).

Patient consent

The patient provided written informed consent.

Author contribution statement

All authors contributed equally to the conception, writing and editing of the manuscript. L Foppiani took care of the patient during hospitalization and in the outpatient department, performed the metabolic and endocrine work-up, conceived the study, analysed the data and wrote the manuscript. MG Poeta evaluated the patient during hospitalization with regard to neurological problems and planned the related work-up (brain imaging procedures and rachicentesis). M Rutigliani analysed the histological specimens and performed immunohistochemical studies. S Parodi performed CT and MR scans and analysed the related images. U Catrambone performed the left adrenalectomy. L Cavalleri performed general anaesthesia and assisted the patient during the surgical and post-surgical periods. G Antonucci revised the manuscript. P Del Monte helped in the endocrine work-up, in the evaluation of hormonal data and in the revision of the manuscript. A Piccardo performed 18F-FDG PET/CT and analysed the related images.

Acknowledgement

The work of Prof Silvia Morbelli in performing and analysing 68Ga-DOTATOC PET/CT is gratefully acknowledged.

References

From https://edm.bioscientifica.com/view/journals/edm/2023/2/EDM22-0308.xml

 

Filed under: adrenal, Cushing's, Rare Diseases, symptoms | Tagged: , , , , | Leave a comment »

Complete and Sustained Remission of Hypercortisolism With Pasireotide Treatment of an Adrenocorticotropic Hormone (Acth)-Secreting Thoracic Neuroendocrine Tumour: an N-Of-1 Trial

Posted on February 7, 2023 by MaryO
Abstract

N-of-1 trials can serve as useful tools in managing rare disease. We describe a patient presenting with a typical clinical picture of Cushing’s Syndrome (CS).

Further testing was diagnostic of ectopic Adrenocorticotropic Hormone (ACTH) secretion, but its origin remained occult. The patient was offered treatment with daily pasireotide at very low doses (300 mg bid), which resulted in clinical and biochemical control for a period of 5 years, when a pulmonary typical carcinoid was diagnosed and dissected. During the pharmacological treatment period, pasireotide was tentatively discontinued twice, with immediate flare of symptoms and biochemical markers, followed by remission after drug reinitiation.

This is the first report of clinical and biochemical remission of an ectopic CS (ECS) with pasireotide used as first line treatment, in a low-grade lung carcinoid, for a prolonged period of 5 years. In conclusion, the burden of high morbidity caused by hypercortisolism can be effectively mitigated with appropriate pharmacological treatment, in patients with occult tumors. Pasireotide may lead to complete and sustained remission of hypercortisolism, until surgical therapy is feasible. The expression of SSTR2 from typical carcinoids may be critical in allowing the use of very low drug doses for achieving disease control, while minimizing the risk of adverse events.

 

Filed under: adrenal, Cancer, Clinical trials, Cushing's, Rare Diseases, Treatments | Tagged: , , , , , , , | Leave a comment »

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