Association of IGF-1 Level with Low Bone Mass in Young Patients with Cushing’s Disease

Abstract

Purpose. Few related factors of low bone mass in Cushing’s disease (CD) have been identified so far, and relevant sufficient powered studies in CD patients are rare. On account of the scarcity of data, we performed a well-powered study to identify related factors associated with low bone mass in young CD patients.

Methods. This retrospective study included 153 CD patients (33 males and 120 females, under the age of 50 for men and premenopausal women). Bone mineral density (BMD) of the left hip and lumbar spine was measured by dual energy X-ray absorptiometry (DEXA). In this study, low bone mass was defined when the Z score was −2.0 or lower. Results. Among those CD patients, low bone mass occurred in 74 patients (48.37%). Compared to patients with normal BMD, those patients with low bone mass had a higher level of serum cortisol at midnight (22.31 (17.95-29.62) vs. 17.80 (13.75-22.77), ), testosterone in women (2.10 (1.33–2.89) vs. 1.54 (0.97–2.05), ), higher portion of male (32.43% vs. 11.54%, ) as well as hypertension (76.12% vs. 51.67%, ), and lower IGF-1 index (0.59 (0.43–0.76) vs. 0.79 (0.60–1.02), ). The Z score was positively associated with the IGF-1 index in both the lumbar spine (r = 0.35153, ) and the femoral neck (r = 0.24418, ). The Z score in the femoral neck was negatively associated with osteocalcin (r = −0.22744, ). Compared to the lowest tertile of the IGF-1 index (<0.5563), the patients with the highest tertile of the IGF-1 index (≥0.7993) had a lower prevalence of low bone mass (95% CI 0.02 (0.001–0.50), ), even after adjusting for confounders such as age, gender, duration, BMI, hypertension, serum cortisol at midnight, PTH, and osteocalcin.

Conclusions. The higher IGF-1 index was independently associated with lower prevalence of low bone mass in young CD patients, and IGF-1 might play an important role in the pathogenesis of CD-caused low bone mass.

1. Introduction

Cushing’s disease (CD), caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary tumor, is a rare disease with approximately 1.2 to 2.4 new cases per million people each year [1].

Osteoporosis has been recognized as a serious consequence of endogenous hypercortisolism since the first description in 1932 [2]. The prevalence of osteoporosis is around 38–50%, and the rate of atraumatic compression fractures is 15.8% in CD patients [3]. After cortisol normalization and appropriate treatment, recovery of the bone impairment occurs slowly (6–9 years) and partially [45]. Hypercortisolemia impairs bone quality through multiple mechanisms [6]. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) play a crucial role in bone growth and development [7]. IGF-1 is considered essential for the longitudinal growth of bone, skeletal maturity, and bone mass acquisition not only during growth but also in the maintenance of bone in adults [8]. Previous research studies revealed that low serum IGF-1 levels were associated with a 40% increased risk of fractures [910], and serum IGF-1 levels could be clinically useful for evaluating the risk of spinal fractures [11]. In Marl Hotta’s research, extremely low or no response of plasma GH to recombinant human growth hormone (hGRH) injection was noted in CD patients. This result suggested that the diminished hGRH-induced GH secretion in patients with Cushing’s syndrome might be caused by the prolonged period of hypercortisolemia [12]. Other surveys indicated that glucocorticoids, suppressing GH–IGF-1 and the hypothalamic-pituitary-gonadal axes, lead to decreased number and dysfunction of osteoblast [13].

However, the exact mechanism is still unclear, and few risk factors for osteoporosis in CD have been identified so far. Until now, relevant and sufficiently powered studies in CD patients have been rare [1415]. Early recognition of the changes in bone mass in CD patients contributes to early diagnosis of bone mass loss and prompt treatment, which could help minimize the incidence of adverse events such as fractures.

On account of the scarcity of data and pressing open questions concerning risk evaluation and management of osteoporosis, we performed a well-powered study to identify the related factors associated with low bone mass in young CD patients at the time of diagnosis.

2. Materials and Methods

2.1. Subjects

This retrospective study enrolled 153 CD patients (33 males and 120 females) from the Department of Endocrinology and Metabolism of Huashan Hospital between January 2010 and February 2021. All subjects were evaluated by the same group of endocrinologists for detailed clinical evaluation. This study, which was in complete adherence to the Declaration of Helsinki, was approved by the Human Investigation Ethics Committee at Huashan Hospital, Fudan University (No. 2017M011). We collected data on demographic characteristics, laboratory tests, and bone mineral density.

Inclusion criteria included the following: (1) willingness to participate in the study; (2) premenopausal women ≥18 years old, men ≥18 years old but younger than 50 years old, and young women (<50 years old) with menstrual abnormalities who were associated with CD after excluding menstrual abnormalities caused by other causes; (3) diagnosis of CD according to the updated diagnostic criteria [16]; and (4) pathological confirmation after transsphenoidal surgery (positive immunochemistry staining with ACTH). Exclusion criteria included Cushing’s syndrome other than pituitary origin.

2.2. Clinical and Biochemical Methods

IGF-1 was measured using the Immulite 2000 enzyme-labeled chemiluminescent assay (Siemens Healthcare Diagnostic, Surrey, UK). Other endocrine hormones, including cortisol (F), 24-hour urinary free cortisol (24hUFC), adrenocorticotropic hormone (ACTH), prolactin (PRL), luteinizing hormone (LH), follicle stimulating hormone (FSH), estrogen (E2), progesterone (P), testosterone (T), thyroid stimulating hormone (TSH), and free thyroxine (FT4), were carried out by the chemiluminescence assay (Advia Centaur CP). Intra-assay and interassay coefficients of variation were less than 8 and 10%, respectively, for the estimation of all hormones.

Bone metabolism markers included osteocalcin (OC), type I procollagen amino-terminal peptide (P1NP), parathyroid hormone (PTH), and 25-hydroxyvitamin D (25(OH)VD), measured in a Roche Cobas e411 analyzer using immunometric assays (Roche Diagnostics, Indianapolis, IN, USA).

The IGF-1 index was defined as the ratio of the measured value to the respective upper limit of the reference range for age and sex. Body mass index (BMI) was calculated using the following formula: weight (kg)/height2 (m2). The bone mineral density (BMD) measuring instrument was Discovery type W dual energy X-ray absorptiometry from the American HOLOGIC company. Quality control tests were conducted every working day. Before examination, the date of birth, height, weight, and menopause date of the examiner were accurately recorded, and then BMD (g/cm2) of the left hip and lumbar spine were measured by DEXA. Z value was used for premenopausal women and men younger than 50 years old, and Z-value = (measured value − mean bone mineral density of peers)/standard deviation of BMD of peers [1718]. In this study, low bone mass was defined as a Z-value of −2.0 or lower.

2.3. Statistical Analysis

The baseline characteristics were compared between CD patients with and without low bone mass by using the Student’s t-test for continuous variables and the χ2 test for category variables. Bone turnover markers, alanine aminotransferase (ALT), triglyceride (TG), IGF-1 index, thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), testosterone (T), 24 hours of urine cortisol (24 h UFC), and serum cortisol at 8 a.m. (F8 am) and at midnight (F24 pm) were not in normal distribution, so variables mentioned above were Log10-transformed, which could be used as continuous variables during statistical analysis. Participants were categorized into three groups according to tertiles of the IGF-1 index: <0.5986, 0.5986–0.8380, and >0.8380. The linear trend across IGF-1 index tertiles was tested using linear regression analysis for continuous variables and the Cochran–Armitage test for categorical variables. We used a multivariate logistic regression model to identify related factors that are independently associated with the risk of low bone mass. Variables included in the multivariate logistic regression model were selected based on the Spearman rank correlation analysis and established traditional low bone mass risk factors as priors. The results were presented as odds ratios (OR) and the corresponding 95% confidence intervals (CI). Significance tests were two-tailed, with  value <0.05 considered statistically significant for all analyses. Statistical analysis was performed using SAS version 9.3 (SAS Institute Inc, Cary, NC, USA).

3. Results

3.1. The Prevalence of Low Bone Mass in Young Cushing’s Disease Patients

From the inpatient system of Huashan hospital, a total of 153 CD patients under the age of 50 for men and premenopausal women (some with menstrual abnormalities were associated with CD) were included, aged from 13 to 49 years, with an average age of 34.25 ± 8.39 years. There were 33 males (21.57%) and 120 females (78.43%). These CD patients included newly diagnosed CD, recurrences of CD, and CD without remission after treatment. There were no differences in the prevalence of different statuses of CD between the two groups (Table 1).

Table 1 
Clinical and biochemical preoperative characteristics of young Cushing’s disease patients according to status of bone mineral density at diagnosis.

Among these CD patients, low bone mass occurred in 74 patients (48.37%), including 24 men and 50 women. The prevalence of low bone mass was 41.67% and 72.73% in female and male CD patients, respectively, and 42 (56.76%) patients suffered from low bone mass in the lumbar spine only, while 10 (13.51%) patients had low bone mass in the femoral neck only, and 22 (29.73%) patients had low bone mass in both parts.

In female patients with low bone mass, 27 (54%) had low bone mass in the lumbar region only, 9 (18%) in the femoral neck only, and 14 (28%) had low bone mass in both parts. For male patients with low bone mass, 16 (66.67%) patients had low bone mass only in the lumbar region, and the rest (8, 33.33%) had low bone mass in both parts.

Ten patients had a history of fragility fractures (6 ribs, 3 vertebrae, 1 femoral neck, and ribs), and all of them achieved low bone mass in BMD.

3.2. Baseline Characteristics of Cushing’s Disease Patients with and without Low Bone Mass

These CD patients were divided into two groups with and without low bone mass (Table 1). Compared to patients without low bone mass, those low bone mass patients had a higher level of diastolic blood pressure (DBP) (97.07 ± 13.69 vs. 89.76 ± 13.43, ), serum creatinine (66.15 ± 24.33 vs. 55.90 ± 13.35, ), uric acid (0.36 ± 0.10 vs. 0.32 ± 0.10, ), cholesterol (5.57 ± 1.30 vs. 5.06 ± 1.47, ), testosterone in women (2.10 (1.33–2.89) vs. 1.54 (0.97–2.05), ), F24 pm (22.31 (17.95–29.62) vs. 17.80 (13.75–22.77), ), and higher portion of male (32.43% vs. 11.54%, ), as well as hypertension (76.12% vs. 51.67%, ). The low bone mass group had a lower IGF-1 index (0.59 (0.43–0.76) vs. 0.79 (0.60–1.02), ) and FT3 level (3.54 (3.16–4.04) vs. 3.98 (3.47–4.45), ) than those without low bone mass. CD patients without low bone mass were more likely to have serum IGF-1 above the upper limit of the normal reference range (ULN) with age-adjusted (18, 26.87% vs. 3, 4.84%, ). No differences of bone turnover makers were found between the two groups.

3.3. Association between Baseline Characteristics and BMD

Spearman’s rank correlation analysis was used to explore the related factors of low bone mass in young CD patients (Table 2). The results indicated that the Z score in the lumbar spine was positively associated with age at diagnosis (r = 0.18801, ), IGF-1 index (r = 0.35153, ), FT3 level (r = 0.24117, ), estradiol in women (r = 0.2361, ), and occurrence of normal menstruation in females (r = 0.2267, ). Meanwhile, SBP (r = −0.21575, ), DBP (r = −0.32538, ), ALT (r = −0.17477, ), serum creatinine (r = −0.36072, ), cholesterol (r = −0.20205, ), testosterone in women (r = −0.2700, ), F8 am (r = −0.18998, ), and serum cortisol at midnight (r = −0.27273, ) were negatively associated with the Z-score in the lumbar spine. The results also illustrated that the Z-score in the femoral neck was positively associated with BMI (r = 0.33926, ), IGF-1 index (r = 0.24418, ), FT3 level (r = 0.20487, ), and occurrence of normal menstruation in females (r = 0.2393, ). Serum creatinine (r = −0.1932, ), osteocalcin (r = −0.22744, ), and testosterone in women (r = −0.2363, ) were negatively associated with the Z-score in the femoral neck.

Table 2 
Spearman rank correlation of BMD and various variables in Cushing’s disease patients.
3.4. IGF-1 Index and Low Bone Mass

Participants were categorized into the following three groups according to tertiles of the preoperative IGF-1 index: <0.5986 (tertiles 1), 0.5986–0.8380 (tertiles 2), and >0.8380 (tertiles 3). With the IGF-1 index increasing, the level of PTH decreased (54.85 (38.35–66.2), 38.9 (26.6–66.9), 36 (25.5–47.05), and ), while other bone metabolism makers, including PINP, osteocalcin, and 25 (OH) VD, showed no differences among the three groups (Figures 1(a)1(d)). With the increase in the IGF-1 index level, the Z-score of both vertebra lumbalis (tertiles 1: −2.4 (−3.3∼−1.5); tertiles 2: −1.9 (−2.3∼−1.0); tertiles 3: −1.15 (−1.9∼−0.4), ) and the neck of femur (tertiles 1: −1.7 (−2.3∼−0.95); tertiles 2: −1.2 (−1.9∼−0.5); tertiles 3: −1.0 (−1.5∼−0.5), ) increased gradually (Figures 2(a) and 2(b)). Meanwhile, prevalence of low bone mass decreased (68.29%, 53.33%, 23.81%, ) (Figure 3(a)) both in the vertebra lumbalis (63.41%, 48.89%, 16.67%, ) and the neck of femur (32.5%, 11.11%, 11.19%, ), with the increasing of the IGF-1 index level (Figures 3(b) and 3(c)).

Figure 1 
Bone turnover makers in three groups according to tertiles of the preoperative IGF-1 index. Tertiles 1: <0.5986, tertiles 2: 0.5986–0.8380, and tertiles 3 >0.8380. a for PINP; b for osteocalcin; c for PTH; d for VD-OH25. (a) p for trend = 0.2601. (b) p for trend = 0.1310. (c) p for trend = 0.008. (d) p for trend = 0.7956.
Figure 2 
Z-score of both the neck of femur and the vertebra lumbalis in three tertiles of the IGF-1 index. a for the neck of femur; b for the vertebra lumbalis. Tertiles 1: <0.5986, tertiles 2: 0.5986–0.8380, and tertiles 3 >0.8380. (a) p for trend = 0.0148. (b) p for trend < 0.0001.
Figure 3 
Prevalence of low bone mass according to tertiles of the preoperative IGF-1 index. With increment of the IGF-1 index level, prevalence of low bone mass decreased, both in the vertebra lumbalis and neck of femur. Tertiles 1: <0.5986, tertiles 2: 0.5986–0.8380, and tertiles 3 >0.8380. (a) p for trend = 0.0002. (b) p for trend = 0.0169. (c) p for trend < 0.0001.

In the logistic regression analysis of the related factors of low bone mass, most of the potentially relevant factors were put into this model; only the IGF-1 index was still significantly negatively associated with the prevalence of low bone mass after adjusting for covariables. The results indicated that compared to the patients in the lowest tertile of the IGF-1 index (<0.5563), those with the highest tertile of the IGF-1 index (≥0.7993) had a lower prevalence of low bone mass (95% CI 0.16 (0.06–0.41), ). After adjusting for age, gender, and BMI, the patients in the highest tertile of the IGF-1 index still conferred a lower prevalence of low bone mass (95% CI 0.15 (0.06–0.42), ). The association between the IGF-1 index and low bone mass still existed (95% CI 0.02 (0.001–0.5), ) even after adjusting for age, gender, CD duration, BMI, hypertension, dyslipidemia, diabetes, ALT, Scr, FT3, F24 pm, PTH, and osteocalcin (Table 3). In comparison to the reference population, the participants in the middle tertile of the IGF-1 index (0.5563–0.7993) had no different risk of low bone mass.

Table 3 
Association between the preoperative IGF-1 index and the risk of low bone mass.

4. Discussion

Our results revealed that low bone mass occurred in around half of young CD patients, affecting more males than females, and mostly in the lumbar spine. The CD patients in our study had a high prevalence (48.37%) of low bone mass at the baseline. This was in accordance with the findings of previous research, and the reported prevalence of osteoporosis due to excess endogenous cortisol ranges from 22% to 59% [1925]. In this study, CD patients’ lumbar vertebrae were more severely affected than the neck of the femur. It is reported that lumbar vertebrae, containing more trabecular bone than femur neck, were more vulnerable to endogenous cortisol [26].

Our results also indicated that men were more prone to low bone mass than women in CD, which was in accordance with several other studies [232728]; possibly, the deleterious effect of cortisol excess on BMD might overrule the protective effects of sex hormones, and men were more often hypogonadal compared with women in CD patients. In our study, patients with low bone mass had a significantly higher level of F24 pm. Both cortisol levels in the morning and at midnight, were negatively associated with the Z-score of BMD in the lumbar spine at diagnosis. But these results were not seen in the femoral neck at diagnosis. This further indicated that lumbar vertebrae were more vulnerable to endogenous cortisol. BMI was considered to be associated with bone mass [29]. In our study, higher BMI was associated with higher BMD at diagnosis in the femur neck but not in the lumbar vertebrae, consistent with other studies [30].

Interestingly, besides the above known related factors, we also found that a higher level of the IGF-1 index was strongly associated with a lower prevalence of low bone mass, both in the vertebra lumbalis and the neck of the femur, independently of age, gender, duration, BMI, hypertension, dyslipidemia, diabetes, level of ALT, creatinine, FT3, and F24 pm. The IGF-1 index was also positively associated with the BMD Z-score, both in the lumbar spine and the femoral neck. So far, there have been few studies concerning the association between IGF-1 and low bone mass in Cushing’s disease patients. As we know, GH [3132] and IGF-1 [33] have been demonstrated to increase both bone formation (e.g., collagen synthesis) and bone resorption. However, in CD patients, glucocorticoids resulted in decreased number and dysfunction of osteoblasts by inhibiting GH-IGF-1 axes [3435]. In vitro studies suggested that at high concentrations of glucocorticoids, a decreased release of GHRH had been reported [3638]; therefore, GH-IGF-1 axes were inhibited. IGF-1 possessed anabolic mitogenic actions in osteoblasts while reducing the anabolic actions of TGF-β [39]. The decrease in IGF-1 might be a risk factor for low bone mass in CD patients. In vitro studies had also indicated that the suppressive effects of glucocorticoids on osteoblast function can be partially reversed by GH or IGF treatment [8]. In recent years, some studies have also shown that patients with untreated Cushing’s disease may have elevated IGF-1, and mildly elevated IGF-1 in Cushing’s disease does not imply pathological growth hormone excess. Higher IGF-1 levels could predict better outcomes in CD [4041]. Possible mechanisms were not clear, which might involve changes in IGF binding proteins (IGFBPs), interference in IGFBP fragments, IGF-1 synthesis or clearance, and/or the effects of hyperinsulinism induced by excess glucocorticoids. In our study, the results also showed that IGF-1 was an independent protective factor for low bone mass in CD patients.

Our study was one of the few well-powered research studies on the association of IGF-1 levels with low bone mass in young CD patients. These represented important strengths of our study, especially given the rarity of CD. The main limitation of this study was its retrospective nature. This could not prove causality. A prospective study should be conducted to explore the causality between IGF-1 and osteoporosis in CD patients. In addition, this study lacked morphometric data for spinal fractures in all patients, which may underestimate the incidence of fractures and osteoporosis. However, our study indicated that a lower IGF-1 index level was significantly associated with low bone mass in young CD patients, which might provide a new aspect to understand the possible risk factors and mechanism of osteoporosis in CD patients.

In conclusion, our study found that a higher IGF-1 index was independently and significantly associated with decreased prevalence of low bone mass in young CD patients, drawing attention to the role of IGF-1 in the pathogenesis of CD-caused low bone mass and may support the exploration of this pathway in therapeutic agent development in antiosteoporosis in CD.

Data Availability

The data used to support the findings of the study are available on request from the authors.

Additional Points

Through a retrospective study of a large sample of Cushing’s disease (CD) patients from a single center, we found that a higher IGF-1 index was independently associated with a lower prevalence of low bone mass in young CD patients and IGF-1 might play an important role in the pathogenesis of CD-caused low bone mass.

Disclosure

Wanwan Sun and Quanya Sun were the co-first authors.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Authors’ Contributions

Wanwan Sun analyzed the data and wrote the manuscript. Quanya Sun collected the data. Hongying Ye and Shuo Zhang conducted the study design and quality control. All authors read and approved the final manuscript. Wanwan Sun and Quanya Sun contributed equally to this work.

Acknowledgments

The present study was supported by grants from the initial funding of the Huashan Hospital (2021QD023). The study was also supported by grants from Multidisciplinary Diagnosis and Treatment (MDT) demonstration project in research hospitals (Shanghai Medical College, Fudan University, no: DGF501053-2/014).

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Copyright © 2023 Wanwan Sun et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

High-resolution Contrast-enhanced MRI With Three-Dimensional Fast Spin Echo Improved the Diagnostic Performance for Identifying Pituitary Microadenomas In Cushing’s Syndrome

Abstract

Objectives

To assess the diagnostic performance of high-resolution contrast-enhanced MRI (hrMRI) with three-dimensional (3D) fast spin echo (FSE) sequence by comparison with conventional contrast-enhanced MRI (cMRI) and dynamic contrast-enhanced MRI (dMRI) with 2D FSE sequence for identifying pituitary microadenomas.

Methods

This single-institutional retrospective study included 69 consecutive patients with Cushing’s syndrome who underwent preoperative pituitary MRI, including cMRI, dMRI, and hrMRI, between January 2016 to December 2020. Reference standards were established by using all available imaging, clinical, surgical, and pathological resources. The diagnostic performance of cMRI, dMRI, and hrMRI for identifying pituitary microadenomas was independently evaluated by two experienced neuroradiologists. The area under the receiver operating characteristics curves (AUCs) were compared between protocols for each reader by using the DeLong test to assess the diagnostic performance for identifying pituitary microadenomas. The inter-observer agreement was assessed by using the κ analysis.

Results

The diagnostic performance of hrMRI (AUC, 0.95–0.97) was higher than cMRI (AUC, 0.74–0.75; p ≤ .002) and dMRI (AUC, 0.59–0.68; p ≤ .001) for identifying pituitary microadenomas. The sensitivity and specificity of hrMRI were 90–93% and 100%, respectively. There were 78% (18/23) to 82% (14/17) of the patients, who were misdiagnosed on cMRI and dMRI and correctly diagnosed on hrMRI. The inter-observer agreement for identifying pituitary microadenomas was moderate on cMRI (κ = 0.50), moderate on dMRI (κ = 0.57), and almost perfect on hrMRI (κ = 0.91), respectively.

Conclusions

The hrMRI showed higher diagnostic performance than cMRI and dMRI for identifying pituitary microadenomas in patients with Cushing’s syndrome.

Key Points

• The diagnostic performance of hrMRI was higher than cMRI and dMRI for identifying pituitary microadenomas in Cushing’s syndrome.

• About 80% of patients, who were misdiagnosed on cMRI and dMRI, were correctly diagnosed on hrMRI.

• The inter-observer agreement for identifying pituitary microadenomas was almost perfect on hrMRI.

Introduction

Cushing’s syndrome, caused by excessive exposure to glucocorticoids, is associated with considerable morbidity and increased mortality [1]. Cushing’s syndrome has diverse manifestations, including central obesity, moon facies, purple striae, and hypertension [2]. Cushing’s disease, due to adrenocorticotropic hormone (ACTH) hypersecretion from pituitary adenomas, is the most common etiology of ACTH-dependent Cushing’s syndrome [12]. According to the Endocrine Society Clinical Practice Guideline, transsphenoidal surgery is the first-line treatment for Cushing’s disease [3]. The identification of pituitary adenomas on preoperative MRI can significantly increase the postoperative remission rate from 50 to 98% [4]. Therefore, it is critical to identify pituitary adenomas on MRI before surgery.

However, there are considerable challenges in identifying ACTH-secreting pituitary adenomas. This is because about 90% of the tumors are microadenomas (less than 10 mm in size) and the median diameter at surgery is about 5 mm [56]. Conventional contrast-enhanced MRI (cMRI) using a two-dimensional (2D) fast spin echo (FSE) sequence has been routinely used to acquire images with 2- to 3-mm slice thickness, but some microadenomas are difficult to be identified on cMRI, resulting in false negatives reported in up to 50% of patients with Cushing’s disease [7]. Dynamic contrast-enhanced MRI (dMRI) increases the sensitivity of identifying pituitary adenomas to 66% [8], but it also increases false positives at the same time [910]. The 3D spoiled gradient recalled (SPGR) sequence has been introduced in high-resolution contrast-enhanced MRI (hrMRI) to acquire images with 1- to 1.2-mm slice thickness. It is reported that the 3D SPGR sequence is superior to the 2D FSE sequence in the identification of pituitary adenomas with a sensitivity of up to 80% [11,12,13], but it cannot satisfy the clinical needs that about 20% of the lesions are still missed. Therefore, techniques are needed that can help better identify pituitary adenomas, particularly microadenomas. Previously, the 3D FSE sequence was recommended in patients with hyperprolactinemia [14]. Recently, the 3D FSE sequence has developed rapidly and can provide superior image quality with diminished artifacts [15]. Sartoretti et al demonstrated in a very effective fashion that the 3D FSE sequence is a reliable alternative for pituitary imaging in terms of image quality [16]. However, to our knowledge, few studies have investigated the diagnostic performance of 3D FSE sequences for identifying ACTH-secreting pituitary adenomas, particularly microadenomas.

The aim of our study was to assess the diagnostic performance of hrMRI with 3D FSE sequence by comparison with cMRI and dMRI with 2D FSE sequence for identifying ACTH-secreting pituitary microadenomas in patients with Cushing’s syndrome.

Materials and methods

This single-institutional retrospective study was approved by the Institutional Review Board of our hospital. The study was conducted in accordance with the Helsinki Declaration. The informed consent was waived due to the retrospective nature of the study.

Study participants

We retrospectively reviewed the medical records and imaging studies of 186 consecutive patients with ACTH-dependent Cushing’s syndrome, who underwent a combined protocol of cMRI, dMRI, and hrMRI from January 2016 to December 2020. Postoperative patients with Cushing’s disease (n = 97), patients with ectopic ACTH syndrome who underwent pituitary exploration (n = 2), and patients with macroadenomas (n = 5) or lack of pathology (n = 13) were excluded from the study. Finally, 69 patients with ACTH-dependent Cushing’s syndrome were included in the current study (Fig. 1) and the patients included were all surgically confirmed.

Fig. 1
figure 1

Flowchart of patient inclusion/exclusion process and image analysis. ACTH adrenocorticotropic hormone, CD Cushing’s disease, EAS ectopic ACTH syndrome, T1WI T1-weighted imaging, T2WI T2-weighted imaging

MRI protocol

All the patients were imaged on a 3.0 Tesla MR scanner (Discovery MR750w, GE Healthcare) using an 8-channel head coil. The MRI protocol included coronal T2-weighted imaging, coronal T1-weighted imaging, and sagittal T1-weighted imaging before contrast injection. After contrast injection of gadopentetate dimeglumine (Gd-DTPA) at 0.05 mmol/kg (0.1 mL/kg) with a flow rate of 2 mL/s followed by a 10-mL saline solution flush, dMRI and cMRI with 2D FSE sequence were obtained first, and hrMRI with 3D FSE sequence using variable flip angle technique was performed immediately afterward. Detailed acquisition parameters are presented in Table S1.

Image analysis: diagnostic performance

Image interpretation was independently conducted by two experienced neuroradiologists (F.F. and H.Y. with 25 and 16 years of experience in neuroradiology, respectively), who were blinded to patient information. The evaluation order of cMRI, dMRI, and hrMRI sequences was randomized. The identification of pituitary microadenomas on images was scored based on a three-point scale (0 = poor; 1 = fair; 2 = excellent). Scores of 1 or 2 represented the identification of the lesion. Reference standards were established by using all available imaging, clinical, surgical, and pathological resources, with a multidisciplinary team approach.

Image analysis: image quality

Two readers (Z.L. and B.H. with 4 years of experience in radiology, respectively) were asked to assess the image quality of cMRI, dMRI, and hrMRI. Before exposure to images used in the current study, these readers underwent a training session to make sure that they were comparable to the experienced neuroradiologists in terms of image quality assessment. Images were presented in a random order. Image quality was assessed by using a 5-point Likert scale [17], including overall image quality (1 = non-diagnostic; 2 = poor; 3 = fair; 4 = good; 5 = excellent), sharpness (1 = non-diagnostic; 2 = not sharp; 3 = a little sharp; 4 = moderately sharp; 5 = satisfyingly sharp), and structural conspicuity (1 = non-diagnostic; 2 = poor; 3 = fair; 4 = good; 5 = excellent). An example of image quality assessment is shown in Table S2. Final decision was made through a consensus agreement.

The mean signal intensity of pituitary microadenomas, pituitary gland, and noise on cMRI, dMRI, and hrMRI was measured using an operator-defined region of interest. For noise, a 10-mm2 region of interest was placed in the background, and noise was defined as the standard deviation of the signal intensity of the background [17]. For pituitary microadenomas and pituitary gland, the region of interest should include a representative portion of the structure. The mean signal intensity of the pituitary microadenoma was replaced with that of the pituitary gland when no microadenoma was identified. A signal-to-noise ratio (SNR) was defined as the mean signal intensity of the pituitary microadenoma divided by noise. A contrast-to-noise ratio (CNR) was defined as the absolute difference of the mean signal intensity between the normal pituitary gland and pituitary microadenomas divided by noise [17]. Supplementary Fig. 1 shows how to measure the SNR and CNR with the region of interest in a contrast-enhanced pituitary MRI. Supplementary Fig. 2 shows the selection of images for the SNR and CNR calculation.

Statistical analysis

The κ analysis was conducted to assess the inter-observer agreement for identifying pituitary microadenomas. The κ value was interpreted as follows: below 0.20, slight agreement; 0.21–0.40, fair agreement; 0.41–0.60, moderate agreement; 0.61–0.80, substantial agreement; greater than 0.80, almost perfect agreement.

To assess the diagnostic performance of cMRI, dMRI, and hrMRI for identifying pituitary microadenomas, the receiver operating characteristic curves were plotted and the area under curves (AUCs) were compared between MR protocols for each reader by using the DeLong test. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. The Mann–Whitney U test was used to evaluate the difference in image quality scores and the Wilcoxon signed-rank test was used to evaluate SNR and CNR measurements between MR protocols. A p value of less than 0.05 was considered statistically significant. Statistical analysis was performed using MedCalc Statistical Software (version 20.0.15; MedCalc Software) and SPSS Statistics (version 22.0; IBM).

Results

Clinical characteristics

A total of 69 patients (median age, 39 years; interquartile range [IQR], 29–54 years; 38 women [55%]) with ACTH-dependent Cushing’s syndrome were included in the study and their clinical characteristics are shown in Table 1. Among the 69 patients, 60 (87%) patients were diagnosed with Cushing’s disease and 9 (13%) were ectopic ACTH syndrome. The median disease course was 36 months (IQR, 12–78 months). The median serum cortisol, ACTH, and 24-h urine free cortisol level before surgery were 33.0 μg/dL (IQR, 25.1–40.1 μg/dL; normal range 4.0–22.3 μg/dL), 77.2 ng/L (IQR, 55.0–124.0 ng/L; normal range 0–46 ng/L), and 422.0 μg (IQR, 325.8–984.6 μg; normal range 12.3–103.5 μg), respectively. The median serum cortisol and 24-h urine free cortisol level after surgery were 3.0 μg/dL (IQR, 1.8–18.4 μg/dL) and 195.6 μg (IQR, 63.5–1240.3 μg), respectively. The median diameter of pituitary microadenomas was 5 mm (IQR, 4–5 mm), ranging from 3 to 9 mm.

Table 1 Clinical characteristics of the patients

Diagnostic performance of cMRI, dMRI, and hrMRI for identifying pituitary microadenomas

The inter-observer agreement for identifying pituitary microadenomas by κ statistic between two readers was moderate on cMRI (κ = 0.50), moderate on dMRI (κ = 0.57), and almost perfect on hrMRI (κ = 0.91), respectively.

The diagnostic performance for identifying pituitary microadenomas on cMRI, dMRI, hrMRI, and combined cMRI and dMRI is summarized in Table 2. For reader 1, the diagnostic performance of hrMRI (AUC, 0.95; 95%CI: 0.87, 0.99) was higher than that of cMRI (AUC, 0.75; 95%CI: 0.63, 0.85; p = 0.002), dMRI (AUC, 0.59; 95%CI: 0.47, 0.71; p < 0.001), and combined cMRI and dMRI (AUC, 0.65; 95%CI: 0.53, 0.76; p = 0.001). For reader 2, the diagnostic performance of hrMRI (AUC, 0.97; 95%CI: 0.89, 1.00) was higher than that of cMRI (AUC, 0.74; 95%CI: 0.63, 0.84; p = 0.001), dMRI (AUC, 0.68; 95%CI: 0.56, 0.79; p = 0.001), and combined cMRI and dMRI (AUC, 0.70; 95%CI: 0.58, 0.80; p = 0.003).

Table 2 Diagnostic performance of cMRI, dMRI, and hrMRI for identifying pituitary microadenomas

For reader 1, 23 of the 69 patients (33%) were misdiagnosed on both cMRI and dMRI, but 18 of the 23 misdiagnosed patients (78%) were correctly diagnosed on hrMRI. For reader 2, 17 of the 69 patients (25%) were misdiagnosed on both cMRI and dMRI, but 14 of the 17 misdiagnosed patients (82%) were correctly diagnosed on hrMRI.

Figure 2 shows that a 5-mm pituitary microadenoma was identified on preoperative pituitary MRI. The margin of the lesion was fully delineated on hrMRI, but not on cMRI and dMRI. Figure 3 shows that a 3-mm pituitary microadenoma was missed on cMRI, but identified on dMRI and hrMRI. Figure 4 shows that a 5-mm pituitary microadenoma was correctly diagnosed on hrMRI, but missed on cMRI or dMRI. Figure 5 shows that a 4-mm pituitary microadenoma was evident on coronal images as well as reconstructed axial and reconstructed sagittal images on hrMRI.

Fig. 2

figure 2

Images in a 56-year-old man with Cushing’s disease. The 5-mm pituitary microadenoma (arrow) can be identified on (a) coronal contrast-enhanced T1-weighted image and (b) coronal dynamic contrast-enhanced T1-weighted image obtained with two-dimensional (2D) fast spin echo (FSE) sequence, but the margin is not fully delineated. The lesion (arrow) is well delineated on (c) coronal contrast-enhanced T1-weighted image on high-resolution MRI obtained with 3D FSE sequence. d Intraoperative endoscopic photograph during transsphenoidal surgery after exposure of the sellar floor shows a round pituitary microadenoma (arrow)

Fig. 3

figure 3

Images in a 34-year-old woman with Cushing’s disease. No tumor is identified on (a) coronal contrast-enhanced T1-weighted image obtained with two-dimensional (2D) fast spin echo (FSE) sequence. The 3-mm pituitary microadenoma (arrow) with delayed enhancement is identified on the left side of the pituitary gland on (b) coronal dynamic contrast-enhanced T1-weighted image obtained with 2D FSE sequence and (c) coronal contrast-enhanced T1-weighted image on high-resolution MRI obtained with 3D FSE sequence. d Intraoperative endoscopic photograph during transsphenoidal surgery shows a 3-mm pituitary microadenoma (arrow)

Fig. 4

figure 4

Images in a 43-year-old man with Cushing’s disease. The lesion is missed on (a) coronal contrast-enhanced T1-weighted image and (b) coronal dynamic contrast-enhanced T1-weighted image obtained with two-dimensional (2D) fast spin echo (FSE) sequence. c Coronal contrast-enhanced T1-weighted image on high-resolution MRI obtained with 3D FSE sequence shows a round pituitary microadenoma (arrow) measuring approximately 5 mm with delayed enhancement on the left side of the pituitary gland. d Intraoperative endoscopic photograph for microsurgical resection of the 5-mm pituitary microadenoma (arrow)

Fig. 5

figure 5

Images in a 48-year-old woman with Cushing’s disease. Preoperative high-resolution contrast-enhanced MRI using three-dimensional fast spin echo sequence shows a 4-mm pituitary microadenoma (arrow) with delayed enhancement is well delineated on the left side of the pituitary gland on (a) coronal, (b) reconstructed axial, and (c) reconstructed sagittal contrast-enhanced T1-weighted images. d Intraoperative endoscopic photograph during transsphenoidal surgery after exposure of the sellar floor shows a round pituitary microadenoma (arrow)

Image quality of cMRI, dMRI, and hrMRI

Image quality scores of cMRI, dMRI, and hrMRI are presented in Table 3. Scores for overall image quality, sharpness, and structural conspicuity on hrMRI (overall image quality, 5.0 [IQR, 5.0–5.0]; sharpness, 5.0 [IQR, 4.5–5.0]; structural conspicuity, 5.0 [IQR, 5.0–5.0]) were higher than those on cMRI (overall image quality, 4.0 [IQR, 3.5–4.0]; sharpness, 4.0 [IQR, 3.0–4.0]; structural conspicuity, 4.0 [IQR, 4.0–4.0]; p < 0.001 for all) and dMRI (overall image quality, 4.0 [IQR, 4.0–4.0]; sharpness, 4.0 [IQR, 4.0–4.0]; structural conspicuity, 4.0 [IQR, 4.0–4.5]; p < 0.001 for all).

Table 3 Image quality scores on cMRI, dMRI, and hrMRI

The SNR and CNR measurements are shown in Table 4. The SNR of the pituitary microadenomas on hrMRI (67.5 [IQR, 51.2–92.1]) was lower than that on cMRI (82.3 [IQR, 61.8–127.2], p < 0.001), but higher than that on dMRI (53.9 [IQR, 35.2–72.6], p = 0.001). The CNR on hrMRI (26.2 [IQR, 15.1–41.0]) was higher than that on cMRI (10.6 [IQR, 0–42.6], p = 0.023) and dMRI (11.2 [IQR, 0–29.8], p < 0.001).

Table 4 SNR and CNR on cMRI, dMRI, and hrMRI

Discussion

The identification of pituitary microadenomas is considerably challenging but critical in patients with ACTH-dependent Cushing’s syndrome. Our study demonstrated that hrMRI with 3D FSE sequence had higher diagnostic performance (AUC, 0.95–0.97) than cMRI (AUC, 0.74–0.75; p ≤ 0.002) and dMRI (AUC, 0.59–0.68; p ≤ 0.001) for identifying pituitary microadenomas. To our knowledge, there are no previous studies specifically evaluating the identification of pituitary microadenomas on hrMRI with 3D FSE sequence by comparison with cMRI and dMRI in patients with ACTH-dependent Cushing’s syndrome, and this is the largest study conducted in ACTH-secreting microadenomas with a sensitivity of more than 90%.

Recently, techniques for pituitary evaluation have developed rapidly. Because of false negatives and false positives on cMRI and dMRI using 2D FSE sequence [7910], a 3D SPGR sequence was introduced for identifying pituitary adenomas. Previous studies demonstrated that the 3D SPGR sequence performed better than the 2D FSE sequence in the identification of pituitary adenomas with a sensitivity of up to 80% [11,12,13]. In patients with hyperprolactinemia, the 3D FSE sequence was recommended [14] and the 3D FSE sequence has rapidly developed recently with superior image quality [1516], suggesting that the 3D FSE sequence may be a reliable alternative for identifying pituitary adenomas. However, to our knowledge, few studies have investigated the diagnostic performance of the 3D FSE sequence for identifying ACTH-secreting pituitary adenomas. To fill the gaps, we conducted the current study and revealed that images obtained with the 3D FSE sequence had higher sensitivity (90–93%) in identifying pituitary microadenomas, than that in previous studies using the 3D SPGR sequence [811,12,13].

There is a trade-off between spatial resolution and image noise. The reduced slice thickness can overcome the partial volume averaging effect, but it is associated with increased image noise [17]. Strikingly, our study showed that hrMRI had higher image quality scores than cMRI and dMRI, in terms of overall image quality, sharpness, and structural conspicuity. The SNR of the pituitary microadenomas on cMRI was slightly higher than that on hrMRI in our study. This is because the SNR was calculated as the mean signal intensity of the pituitary gland (instead of the pituitary microadenoma) divided by noise when no microadenoma was identified, and the mean signal intensity of the pituitary gland is higher than that of the pituitary microadenoma. About 40% of pituitary microadenomas were missed on cMRI, whereas less than 10% of pituitary microadenomas were missed on hrMRI. Given the situation mentioned above, the SNR on hrMRI was lower than that on cMRI. However, the CNR on hrMRI was significantly higher than that on cMRI and dMRI. Therefore, hrMRI in our study can dramatically improve the spatial resolution with high CNR, enabling the better identification of pituitary microadenomas.

The identification of pituitary adenomas on preoperative MRI in patients with ACTH-dependent Cushing’s syndrome could help the differential diagnosis of Cushing’s syndrome and aids surgical resection of lesions. It should be noted that most of the pituitary adenomas in patients with Cushing’s disease are microadenomas [56]. In our study, all the tumors are microadenomas with a median diameter of 5 mm (IQR, 4–5 mm), making the diagnosis more challenging. The sensitivity of identifying pituitary adenomas decreased from 80 to 72% after excluding macroadenomas in a previous study [12], whereas the sensitivity of identifying pituitary microadenomas in our study was 90–93% on hrMRI. In the current study, hrMRI performed better than cMRI, dMRI, and combined cMRI and dMRI, with high AUC (0.95–0.97), high sensitivity (90–93%), and high specificity (100%), superior to previous studies [811,12,13]. The high sensitivity of hrMRI for identifying pituitary adenomas will help surgeons improve the postoperative remission rate [4]. The high specificity of hrMRI will assist clinicians to consider ectopic ACTH syndrome, and then perform imaging to identify ectopic tumors. Besides, the inter-observer agreement for identifying pituitary microadenomas was almost perfect on hrMRI (κ = 0.91), which was moderate on cMRI (κ = 0.50) and dMRI (κ = 0.57). Therefore, hrMRI using the 3D FSE sequence is a potential alternative that can significantly improve the identification of pituitary microadenomas.

Limitations of the study included its retrospective nature and the relatively small sample size in patients with ectopic ACTH syndrome as negative controls. The bias may be introduced in the patient inclusion process. Only those patients who underwent all the cMRI, dMRI, and hrMRI scans were included. In fact, some patients will bypass hrMRI when obvious pituitary adenomas were detected on cMRI and dMRI. These patients were not included in the current study because of lack of hrMRI findings. Given the situation, the sensitivity of identifying pituitary adenomas will be higher with the enrollment of these patients. Besides, the timing of the sequence acquisition after contrast injection is essential [16] and bias may be introduced due to the postcontrast enhancement curve of both the pituitary gland and the microadenoma [14]. In the future, a prospective study with different sequence acquisition orders is needed to minimize possible interference caused by the postcontrast enhancement curve. Moreover, a larger sample size is also needed to verify the diagnostic performance of hrMRI using 3D FSE sequence for identifying pituitary microadenomas and to determine whether it can replace 2D FSE or 3D SPGR sequences for routinely evaluating the pituitary gland.

In conclusion, hrMRI with 3D FSE sequence showed higher diagnostic performance than cMRI and dMRI for identifying pituitary microadenomas in patients with Cushing’s syndrome.

Abbreviations

ACTH:
Adrenocorticotropic hormone
AUC:
Area under the receiver operating characteristics curve
cMRI:
Conventional contrast-enhanced MRI
CNR:
Contrast-to-noise ratio
dMRI:
Dynamic contrast-enhanced MRI
FSE:
Fast spin echo
hrMRI:
High-resolution contrast-enhanced MRI
IQR:
Interquartile range
SNR:
Signal-to-noise ratio
SPGR:
Spoiled gradient re

called

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Acknowledgements

We thank Dr. Kai Sun, Medical Research Center, Peking Union Medical College Hospital, for his guidance on the statistical analysis in this study.

Funding

This study has received funding from the National Natural Science Foundation of China (grant 82071899), the National Key Research and Development Program of China (grants 2016YFC1305901, 2020YFA0804500), the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (grants 2017-I2M-3–008, 2021-I2M-1–025), the Beijing Natural Science Foundation (grant L182067) and National High Level Hospital Clinical Research Funding (2022-PUMCH-B-067, 2022-PUMCH-B-114).

Author information

Author notes

  1. Zeyu Liu and Bo Hou contributed equally to this work and share first authorship
  2. Hui You and Feng Feng contributed equally to this work and share corresponding authorship

Authors and Affiliations

  1. Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuaifuyuan Wangfujing Dongcheng Distinct, Beijing, 100730, China

    Zeyu Liu, Bo Hou, Hui You, Mingli Li & Feng Feng

  2. Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuaifuyuan Wangfujing Dongcheng Distinct, Beijing, 100730, China

    Lin Lu, Lian Duan & Huijuan Zhu

  3. Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuaifuyuan Wangfujing Dongcheng Distinct, Beijing, 100730, China

    Kan Deng & Yong Yao

  4. State Key Laboratory of Complex Severe and Rare Disease, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuaifuyuan Wangfujing Dongcheng Distinct, Beijing, 100730, China

    Yong Yao, Huijuan Zhu & Feng Feng

Corresponding authors

Correspondence to Hui You or Feng Feng.

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The scientific guarantor of this publication is Feng Feng.

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The authors of this manuscript declare no conflict of interest.

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No complex statistical methods were necessary for this paper.

Informed consent

Written informed consent was waived by the Institutional Review Board.

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• retrospective

• diagnostic or prognostic study

• performed at one institution

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

Abstract

Rationale:

Ectopic ACTHproducing 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 ACTHproducing 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 ACTHproducing 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 ACTHproducing 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.

Hide full references list
Keywords:

clivus regionCushingEctopic ACTHlike appearanceproducing pituitary adenoma

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

Cushing’s Disease Associated With Partially Empty Sella Turcica Syndrome

Abstract

The association between empty sella turcica (EST) syndrome and Cushing’s disease has been rarely reported. It is plausible to hypothesize that EST syndrome in association with Cushing’s disease can be attributed to intracranial hypertension. In this case report, we present a 47-year-old male patient who presented with weight loss, fatigue, easy bruising, acanthosis nigricans, and skin creases hyperpigmentation. Investigations revealed hypokalemia and confirmed the diagnosis of Cushing’s disease. Magnetic resonance imaging (MRI) brain showed a partial EST syndrome and a new pituitary nodule as compared with previous brain imaging. Transsphenoidal surgery was pursued and was complicated by cerebrospinal fluid leakage. This case reflects the rare association of EST syndrome and Cushing’s disease, suggesting the increased risk of postoperative complications in this setting and the diagnostic challenge that EST syndrome imposes. We review the literature for a possible mechanism of this association.

Introduction

Cushing’s disease is commonly caused by an adrenocorticotropic hormone (ACTH)-producing pituitary adenoma, which can be very challenging to be seen on brain magnetic resonance imaging (MRI) [1]. Empty sella turcica (EST) syndrome is a radiological diagnosis of apparently empty turcica secondary to outpouching of the arachnoid mater into the turcica, which can be attributed to intracranial hypertension (ICHTN). This can make the visual diagnosis of pituitary adenoma even more challenging in clinical practice. ICHTN has been also associated with Cushing’s disease and might explain this infrequent association between EST and Cushing’s disease [1]. EST syndrome can be either partial or complete, primary or secondary and has been seen infrequently with Cushing’s disease. In this setting, not only that it is likely to obscure an underlying pituitary lesion, but also it does contribute to the risk of postoperative complications [2].

Case Presentation

A 47-year-old male presented to the emergency department (ED) with slowly progressive generalized limb muscle weakness affecting both distal and proximal muscles over a few weeks and gait instability for three days prior to presentation. He also reported unintentional 40 pounds weight loss over the previous four months. Past medical history was significant for type II diabetes mellitus, hypothyroidism, hypertension, and dyslipidemia. In the ED, vital signs included a blood pressure of 140/90 mmHg, a heart rate of 66 beats per minute, a respiratory rate of 16 cycles per minute, and SpO2 of 97% on room air. Body mass index has decreased to 22 kg/m2 from a baseline of 26 kg/m2 one month prior. On the physical exam, he exhibited cachexia, easy bruising, acanthosis nigricans, and hyperpigmentation of skin creases. All other systems were negative. Complete metabolic panel and complete blood count were obtained showing hyperglycemia of 311 mg/dl, see Table 1. Further lab evaluation showed elevated salivary cortisol at 2.96 microgram/dl (reference range 0.094-1.551 mcg/dl), elevated 24-hour urinary free cortisol at 156 mcg/24 hour (reference 10-100 mcg/24h), positive overnight dexamethasone suppression test with serum cortisol at 2.8 mcg/dl (reference more than 2 mcg/dl), negative anti-adrenal antibodies, normal aldosterone, and elevated dehydroepiandrostenedione at 401 mcg/dl (reference 32-240 mcg/dl), with lack of suppression of the ACTH level at 35.1 pg/ml (reference 10-60 pg/ml). This confirmed the diagnosis of Cushing’s disease.

Variable Finding Reference
Random glucose 311 Less than 200 mg/dl
Sodium 141 137-145 mmol/L
Potassium 2.5 3.5-5.1 mmol/L
Chloride 96 98-107 mmol/L
Bicarbonate 32 22-30 mmol/L
Blood urea nitrogen 32 9-20 mg/dl
Creatinine 0.52 0.66-1.25 mg/dl
Calcium 8.7 8.6-10.3 mg/dl
Total protein 5.5 6.5-8.5 g/dl
Albumin 3.3 3.5-5 g/dl
Total bilirubin 0.6 0.2-1.3 mg/dl
Alkaline phosphatase 115 38-126 U/L
Aspartate transaminase 17 17-59 U/L
Alanine transaminase 39 Less than 49 U/L
White blood cell count 10×10^3 cells/mcl 4-10×1063 cells/mcl
Hemoglobin 15.3 13.7-17.5 g/dl
Platelet 281 150-400×10^3 cells/mcl
Table 1: Lab Findings

Computed tomography (CT) scan of the head was unremarkable. CT scan of the chest was also unremarkable. CT scan of abdomen and pelvis showed no adrenal mass. Ultrasound of the kidneys was unremarkable. Pituitary MRI brain protocol for adenoma showed a partial EST, shortening within neurohypophysis and a new 10 x 8 x 4 mm nodule along the floor of pituitary sella as compared to MRI four years ago (Figure 1).

Magnetic-Resonance-Imaging-(MRI)-Brain
Figure 1: Magnetic Resonance Imaging (MRI) Brain

MRI brain showing partially empty sella turcica syndrome ( black arrow) with a small nodule at the floor of the turcica (white arrow).

The diagnosis of Cushing’s disease was confirmed, and the patient underwent trans-sphenoidal resection of pituitary adenoma. Histological examination showed positive CAM 5.2, positive chromogranin, and ACTH immunostains. The patient presented to the ED five days after discharge home. He stated that he noticed drainage from the nose that transitioned from bloody to clear fluid and has been increasing in quantity for two days with associated intermittent headaches since the surgery. He was afebrile with stable vital signs. No signs of infection were noted on basic labs. These were significant only for mild asymptomatic hyponatremia of 131 mmol/L and hypokalemia of 3.3 mmol/L. The patient was diagnosed with cerebrospinal fluid (CSF) leakage and had a lumbar drain trial. The trial was unsuccessful after several days, and the patient underwent a transnasal endoscopic repair of CSF rhinorrhea using nasoseptal flaps. At an outpatient follow-up one month and three months after the surgery, prior lab abnormalities including hypokalemia, hyponatremia, and hyperglycemia resolved. No further evidence of CSF leakage was appreciated, and he remained asymptomatic.

Discussion

EST syndrome is characterized by herniation of the subarachnoid space into the intrasellar space with compression of the pituitary gland into the posteroinferior wall [3]. This is likely to obscure the presence of underlying pituitary mass. The incidence of EST syndrome in the general population is estimated at 20%. The association between EST syndrome and Cushing’s disease has been reported infrequently. A retrospective study of 68 patients with Cushing’s disease found that 16% of these have EST syndrome [3].

Cushing’s disease usually results from pituitary adenomas secreting ACTH, and even the smallest microadenomas can produce a systemic disease. These microadenomas can be very difficult to recognize on brain MRI [4]. This is complicated in EST syndrome and even further with the possibility of ectopic ACTH production. A retrospective study of 197 patients diagnosed with Cushing’s disease concluded that EST syndrome is associated with higher prevalence of MRI-negative Cushing’s disease. This was attributed to ICHTN and pituitary gland compression [1]. Although surgery is curative in 70-90% of cases, EST syndrome was found to have higher risk of postoperative complications among those with Cushing’s disease including diabetes insipidus, hypopituitarism, and CSF leakage [3]. This is usually because in the case of MRI-negative Cushing’s disease with total EST syndrome, empiric surgical exploration is sought after inferior petrosal sampling confirms the pituitary origin of excess ACTH, and postoperative remission indicates adequate tumor resection [2]. This entails a higher chance of uncertainty and injury to healthy pituitary tissue.

EST syndrome can be either primarily due to defects in the sellar diaphragm or anatomical variant or secondary to ICHTN. EST syndrome has been reported in association with many conditions associated with elevated intracranial pressure including tumors, thrombosis, meningitis, hydrocephalus, and Arnold-Chiari malformation [5]. Reversal of EST syndrome has been reported in those with idiopathic ICHTN with therapy by acetazolamide, ventriculoperitoneal shunt, and lumbar puncture [6,7]. A study has shown correlation between CSF circulation impairment or blockage and EST syndrome [8]. The incidence of EST syndrome in association with symptomatic intracranial hypertension is variable and ranges from 2.5% for total EST syndrome to 94% for partial EST syndrome [9]. Impaired CSF circulation and dynamics have been reported in 77% of patients with EST syndrome [10]. In addition to intracranial hypertension, EST syndrome has also been described in association with obesity, meningioma, pediatric nevoid basal cell carcinoma, therapy for growth hormone deficiency and even in healthy individuals [9]. Lack of symptoms of intracranial hypertension in this patient does not rule it out as intracranial hypertension in EST syndrome represents a spectrum that ranges from asymptomatic, milder intracranial hypertension to symptomatic intracranial hypertension with headache, visual disturbance, and papilledema [10]. This explains the fact that only 8-14% of EST syndrome progress to symptomatic ICHTN, while symptomatic ICHTN has been associated with EST syndrome in 94% of cases.

ICHTN has been seen in association with disturbance of the hypothalamic-pituitary-adrenal axis. This has been reported after surgical and medical treatment of Cushing’s disease, withdrawal of long-term steroid therapy, initial presentation of Addison’s disease, or relative glucocorticoids deficiency [11]. Cortisol excess increases CSF production and reduces its absorption, hence increasing intracranial pressure [12]. Another possible mechanism is the expression of both mineralocorticoid responsive epithelial sodium channel receptors on the basolateral membrane of the CSF producing epithelial cells of the choroid plexus as well as the expression of 11-beta hydroxysteroid dehydrogenase type 1 enzyme, which is a bidirectional enzyme that mainly functions to convert the inactive cortisone to active cortisol. These mechanisms play a role in maintaining the balance between CSF production and absorption [13,14].

In this case, the patient presented some clinical findings that are rarely associated with Cushing’s disease, combined with a radiological feature that masked the true diagnosis. Our patient presented with significant weight loss, rather than central obesity, which is normally associated with Cushing’s disease. Although possible, the increase in ACTH due to Cushing’s disease is not sufficient to cause hyperpigmentation, which is a classical finding of Addison’s disease, where the entire adrenal cortex is usually affected due to an autoimmune destruction; however, the zona glomerulosa of the adrenal cortex produces aldosterone and its deficiency would lead to hyperkalemia [15]. Our patient presented with both hyperpigmentation and hypokalemia.

Conclusions

EST syndrome is an uncommon radiological finding of apparently EST that has been reported in association with ICHTN. The latter has also been seen in association with Cushing’s disease/syndrome. This is likely to result from glucocorticoid excess-induced change in CSF flow dynamics. EST has been infrequently described in association with Cushing’s disease. This association has a clinical implication as it is likely to obscure the visualization of pituitary lesions responsible for Cushing’s disease, contribute to diagnostic uncertainty, and increase the risk of healthy pituitary tissue injury and the risk of postoperative complications including CSF leakage.

References

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From https://www.cureus.com/articles/161111-cushings-disease-associated-with-partially-empty-sella-turcica-syndrome-a-case-report#!/

Seliciclib for the Treatment of Cushing’s Disease Targeting Pituitary

The following is a summary of “Treatment of Cushing Disease With Pituitary-Targeting Seliciclib,” published in the March 2023 issue of Endocrinology & Metabolism by Liu, et al.


Seliciclib (R-roscovitine) has been shown in preclinical studies to inhibit neoplastic corticotroph proliferation and the production of adrenocorticotropic hormone (ACTH) in the pituitary gland. Therefore, for a study, researchers sought to investigate the effectiveness of seliciclib as a pituitary-targeting treatment for patients with Cushing’s disease (CD).

Two prospective, open-label, phase 2 trials were conducted at a tertiary referral pituitary center. Adult patients with de novo, persistent, or recurrent CD received oral seliciclib 400 mg twice daily for four consecutive days each week for four weeks. The primary endpoint in the single-center study was normalization of 24-hour urinary free cortisol (UFC; ≤ 50 µg/24 hours) at the end of the study, and in the multicenter study, the primary endpoint was UFC normalization or a ≥ 50% reduction in UFC from baseline to the end of the study.

Of the 16 patients who consented, 9 were treated with seliciclib. The mean UFC decreased by 42% from 226.4 ± 140.3 µg/24 hours at baseline to 131.3 ± 114.3 µg/24 hours at the end of the study. The longitudinal model showed significant reductions in UFC from baseline to each treatment week. Three patients achieved a ≥ 50% reduction in UFC (range, 55%-75%), and two exhibited a 48% reduction; none achieved UFC normalization. Plasma ACTH decreased by 19% (P = 0.01) in patients with ≥48% UFC reduction. Three patients developed grade ≤ 2 elevated liver enzymes, anemia, and/or elevated creatinine, resolved with dose interruption/reduction. Two patients developed grade 4 liver-related serious adverse events that resolved within four weeks of seliciclib discontinuation.

The results suggested that seliciclib may target pituitary corticotrophs in CD and reverse hypercortisolism. Although potential liver toxicity of seliciclib resolves with treatment withdrawal, a further determination is required to establish the lowest effective dose.

Source: academic.oup.com/jcem/article-abstract/108/3/726/6754906?redirectedFrom=fulltext