Ectopic Adrenocorticotrophic Hormone Syndrome in a 10-Year-Old Girl With a Thymic Neuroendocrine Tumor

Posted on November 29, 2024 by MaryO

Abstract

Background

Thymic neuroendocrine tumor as a cause of Cushing syndrome is extremely rare in children.

Case presentation

We report a case of a 10-year-old girl who presented with typical symptoms and signs of hypercortisolemia, including bone fractures, growth retardation, and kidney stones. The patient was managed with oral ketoconazole, during which she experienced adrenal insufficiency, possibly due to either cyclic adrenocorticotropic hormone (ACTH) secretion or concurrent COVID-19 infection. The patient underwent a diagnostic work-up which indicated the possibility of an ACTH-secreting pituitary neuroendocrine tumor. However, after a transsphenoidal surgery, the diagnosis was not confirmed on histopathological examination. Subsequent bilateral inferior petrosal sinus sampling showed strong indications of the presence of ectopic ACTH syndrome. Detailed rereading of functional imaging studies, including 18F-FDG PET/MRI and 68Ga DOTATOC PET/CT, ultimately identified a small lesion in the thymus. The patient underwent videothoracoscopic thymectomy that confirmed a neuroendocrine tumor with ACTH positivity on histopathological examination.

Conclusion

This case presents some unique challenges related to the diagnosis, management, and treatment of thymic neuroendocrine tumor in a child. We can conclude that ketoconazole treatment was effective in managing hypercortisolemia in our patient. Further, a combination of functional imaging studies can be a useful tool in locating the source of ectopic ACTH secretion. Lastly, in cases of discrepancy in the results of stimulation tests, bilateral inferior petrosal sinus sampling is highly recommended to differentiate between Cushing disease and ectopic ACTH syndrome.

Peer Review reports

Background

In children above seven years of age, the majority of pediatric Cushing syndrome (CS) cases are caused by a pituitary neuroendocrine tumors (PitNET). However, a differential diagnosis of hypercortisolemia in children is often challenging concerning the interpretation of stimulation tests and the fact that up to 50% of PitNET may not be detected on magnetic resonance imaging (MRI) [1]. An ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is extremely rare in children. Its diagnosis is often missed or confused with Cushing disease (CD) [2]. Most ACTH-secreting tumors originate from bronchial or thymic neuroendocrine tumors (NETs), or less commonly, from NETs in other locations. To diagnose EAS, specific functional imaging studies are often indicated to elucidate the source of ACTH production.

Pharmacotherapy may be used before surgery to control hypercortisolemia and its symptoms/signs, or in patients in whom the source of hypercortisolism has not been found (e.g., EAS), or surgery failed. Ketoconazole or metyrapone, as adrenal steroidogenesis blockers, were found to be very efficient, although they exhibit side effects [3].

Furthermore, cyclic secretion of ACTH followed by fluctuating plasma cortisol levels is extremely rare in children, including those with EAS [4, 5]. Therefore, in cyclic EAS, the use of steroid inhibitors or acute illness or trauma can be associated with adrenal insufficiency, which can be life-threatening. Here we describe the clinical features, laboratory and radiological investigations, results, management, and clinical outcome of a 10-year-old girl with a thymic NET presenting with ACTH secretion.

Case presentation

A 10-year-old girl was acutely admitted to our university hospital for evaluation of facial edema and macroscopic hematuria in May 2021. A day before admission, she presented to the emergency room for dysuria, pollakiuria, nausea, and pain in her right lower back. Over the past year she had experienced excessive weight gain with increased appetite and growth retardation (Fig. 1). Her height over three years had shifted from the 34th to the 13th centile (Fig. 1). Her parents noticed facial changes, pubic hair development, increased irritability, and moodiness.

Fig. 1

figure 1

Body weight, body height, and body mass index development of the case patient. The black arrow indicates the first presentation, the blue arrow indicates the start of ketoconazole treatment and the yellow arrow indicates the time of thymectomy. Mid-parental height is indicated by the green line

At admission, she was found to have a moon face with a plethora, few acne spots on forehead, as well as facial puffiness. In contrast to slim extremities, an abnormal fat accumulation was observed in the abdomen. Purple striae were present on abdomen and thighs. She did not present with any bruising, proximal myopathy, or edema. On physical examination, she was prepubertal, height was 135 cm (13th centile), and weight was 37 kg (69th centile) with a BMI of 20.4 kg/m2 (90th centile). She developed persistent hypertension. Her past medical history was uneventful except for two fractures of her upper left extremity after minimal trips one and three years ago, both treated with a caste. Apart from hypothyroidism on the maternal side, there was no history of endocrine abnormalities or tumors in the family.

In the emergency room, the patient was started on sulfonamide, pain medication, and intravenous (IV) fluids. Her hypertensive crises were treated orally with angiotensin-converting enzyme inhibitor or with a combination of adrenergic antagonists and serotonin agonists administered IV. Hypokalemia had initially been treated with IV infusion and then with oral potassium supplements. A low serum phosphate concentration required IV management. The initial investigation carried out in the emergency room found hematuria with trace proteinuria. Kidney ultrasound showed a 5 mm stone in her right ureter with a 20 mm hydronephrosis. She did not pass any kidney stones, however, fine white sand urine analysis reported 100% brushite stone.

Hypercortisolemia was confirmed by repeatedly increased 24-hour urinary free cortisol (UFC), (5011.9 nmol/day, normal range 79.0-590.0 nmol/day). Her midnight cortisol levels were elevated (961 nmol/l, normal range 68.2–537 nmol/l). There was no suppression of serum cortisol after 1 mg overnight dexamethasone suppression test (DST) or after low-dose DST (LDDST). An increased morning plasma ACTH (30.9 pmol/l, normal range 1.6–13.9 pmol/) suggested ACTH-dependent hypercortisolemia. There was no evidence of a PitNET on a 1T contrast-enhanced MRI. The high-dose DST (HDDST) did not induce cortisol suppression (cortisol 1112 nmol/l at 23:00, cortisol 1338 nmol/l at 8:00). Apart from the kidney stone, a contrast-enhanced computed tomography (CT) of her neck, chest, and abdomen/pelvis did not detect any lesion. Various tumor markers were negative and the concentration of chromogranin A was also normal.

A corticotropin-releasing hormone (CRH) stimulation test induced an increase in serum cortisol by 32% at 30 min and ACTH concentration by 67% at 15 min (Table 1). A 3T contrast-enhanced MRI scan of the brain identified a 3 × 2 mm lesion in the lateral right side of the pituitary gland (Fig. 2). An investigation of other pituitary hormones was unremarkable. Apart from low serum potassium (minimal level of 2.8 mmol/l; normal range 3.3–4.7 mmol/l) and phosphate (0.94 mmol/l; normal range 1.28–1.82 mmol/l) concentrations, electrolytes were normal. The bone mineral density assessed by whole dual-energy X-ray absorptiometry was normal.

Fig. 2

figure 2

Coronal and sagittal 3T contrast-enhanced brain MRI scans. A suspected 3 × 2 mm lesion in the lateral right side of the pituitary gland (yellow arrows)

The patient was presented at the multidisciplinary tumor board and it was decided that she undergoes transsphenoidal surgery for the pituitary lesion. No PitNET was detected on histopathological examination and no favorable biochemical changes were noted after surgery. After the patient recovered from surgery, subsequent bilateral inferior petrosal sinus sampling (BIPSS) confirmed EAS as the maximum ratio of central to peripheral ACTH concentrations was only 1.7. During the investigation for tumor localization, she was started on ketoconazole treatment (300 mg/day) to alleviate symptoms and signs of hypercortisolism. Treatment with ketoconazole had a beneficial effect on patient health (Fig. 1). There was a weight loss of 2 kg in a month, a disappearance of facial plethora, and a decrease in vigorous appetite. Her liver function tests remained within the normal range.

Table 1 Result of corticotropin-releasing hormone stimulation test

The 24-hour UFC excretion normalized three weeks after ketoconazole initiation. However, six weeks after continuing ketoconazole therapy (400 mg/day), the patient complained of nausea, vomiting, and diarrhea. She was found to have adrenal insufficiency with a low morning serum cortisol of 10.70 nmol/l (normal range 68.2–537 nmol/l) and salivary cortisol concentrations < 1.5 nmol/l (normal range 1.7–29 nmol/l). She was also found to be positive for COVID-19 infection. Ketoconazole treatment was stopped and our patient was educated to take stress steroids in case of persisting or worsening symptoms. Her clinical status gradually improved and steroids were not required.

Meanwhile, whole-body fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET)/MRI was performed with no obvious hypermetabolic lesion suspicious of a tumor. No obvious accumulation was detected on 68Ga-DOTATOC PET/CT images (Fig. 3). However, a subsequent careful and detailed re-review of the images detected a discrete lesion on 18F-FDG PET/MRI and 68Ga-DOTATOC PET/CT scans in the left anterior mediastinum, in the thymus (Fig. 4).

Fig. 3

figure 3

18F-FDG PET/MRI (A) and 68Ga-DOTATOC (B) PET/CT scans. Whole body MIP reconstructions. Subtle correspondent focal hyperactivity in the left mediastinum (black arrow). The 18F-FDG PET/MRI image courtesy of Prof. Jiri Ferda, MD, PhD, Clinic of the Imaging Methods, University Hospital Plzen, Czech Republic

Fig. 4

figure 4

Axial slices of PET/MRI (A–C) and 68Ga-DOTATOC (D–F) PET/CT scans. Subtle correspondent focal hyperactivity in the left mediastinum (white arrow). No obvious finding on MRI (C) and CT (F) scans. The FDG PET/MRI image courtesy of Prof. Jiri Ferda, MD, PhD, Clinic of the Imaging Methods, University Hospital Plzen, Czech Republic

Three weeks after the episode of adrenal insufficiency and being off ketoconazole treatment, our patient´s pre-surgery laboratory tests showed slightly low morning cortisol 132 nmol/l with surprisingly normal ACTH 2.96 pmol/l (normal range 1.6–13.9 pmol/). Given the upcoming surgery, she was initiated on a maintenance dose of hydrocortisone (15 mg daily = 12.5 mg/m2/day). Further improvement of cushingoid characteristics (improvement of facial plethora and moon face, weight loss) was noticed. Our patient underwent videothoracoscopic surgery, and a hyperplastic thymus of 80 × 70 × 15 mm with a 4 mm nodule was successfully removed. Tumor immunohistochemistry was positive for ACTH, chromogranin A, CD56, and synaptophysin. Histopathological findings were consistent with a well-differentiated NET grade 1. A subsequent genetic screening did not detect any pathogenic variant in the MEN1 gene.

After surgery, hydrocortisone was switched to a stress dose and gradually decreased to a maintenance dose. Antihypertensive medication was stopped and further weight loss was observed after thymectomy. Within a few weeks after the thoracic surgery, the patient entered puberty, her mood improved significantly, and potassium supplements were stopped. Finally, hydrocortisone treatment was stopped ten months after thymectomy.

Discussion and conclusions

The case presented here demonstrates a particularly challenging work-up of the pediatric patient with the diagnosis of CS caused by EAS due to thymic NET. Differentiating CD and EAS can sometimes be difficult, including the use of various laboratory and stimulation tests and their interpretation, as well as proper, often challenging, reading of functional imaging modalities, especially if a discrete lesion is present at an unusual location [1]. When using established criteria for Cushing disease (for the CRH test an increase of cortisol and/or ACTH by ≥ 20% or ≥ 35%, respectively, and a ≥ 50% suppression of cortisol for the HDDST) our patient presented discordant results. The CRH stimulation test induced an increase in cortisol by 32% and ACTH by 67% and the 3T MRI pointed to the right-side pituitary lesion, both to yield false positive results. The HDDST, on the other hand, did not induce cortisol suppression and was against characteristic findings for CD. We did not proceed with desmopressin testing, which also induces an excess ACTH and cortisol response in CD patients and has rarely been used in pediatric patients, except in those with extremely difficult venous access [6]. Recently published articles investigated the reliability of CRH stimulation tests and HDDST and both concluded that the CRH test has greater specificity than HDDST [7, 8]. Elenius et al. suggested optimal response criteria as a ≥ 40% increase of ACTH and/or cortisol (cortisol as the most specific measure of CD) during the CRH test and a ≥ 69% suppression of serum cortisol during HDDST [7]. Using these criteria, the CD would be excluded in our patient. To demonstrate that the proposed thresholds for the test interpretation widely differ, Detomas et al. proposed a ≥ 12% cortisol increase and ≥ 31% ACTH increase during the CRH test to confirm CD [8].

The fact that up to 50% of PitNET may not be detected on MRI [1] and that more than 20% of patients with EAS are reported to have pituitary incidentalomas [9] makes MRI somewhat unreliable in differentiating CD and EAS. However, finally, well-established and generally reliable BIPSS in our patient supported the diagnosis of EAS. Thus, BIPSS is considered a gold standard to differentiate between CD and EAS; however, it can still provide false negative results in cyclic CS if performed in the trough phase [10] or in vascular anomalies or false positive results as in a recent case of orbital EAS [11].

In children, the presence of thymus tissue may be misinterpreted as normal. Among other reports of thymic NET [12], Hanson et al. reported a case of a prepubertal boy in whom a small thymic NET was initially treated as normal thymus tissue on CT [13]. In our case, initially, the lesion was not detected on the 18F-FDG and 68Ga-DOTATOC PET scans. A small thymic NET was visible only after a detailed and careful re-reading of both PET scans. Although somatostatin receptor (SSR) PET imaging may be helpful in identifying ectopic CRH- or ACTH-producing tumors, there are still some limitations [13]. For example, in the study by Wannachalee et al., 68Ga-DOTATATE identified suspected primary lesions causing ECS in 65% of patients with previously occult tumors and was therefore concluded as a sensitive method for primary as well as metastatic tumors [14]. In our patient, the final correct diagnosis was based on the results of both PET scans. This is in full support of the article published by Liu et al. who concluded that 18F-FDG and SSR PET scans are complementary in determining the proper localization of ectopic ACTH production [15]. Additionally, it is worth noting that not all NETs stain positively for ACTH which may present a burden in its identification.

To control hypercortisolemia, both ketoconazole and metyrapone were considered in our patient. Due to the side effects of metyrapone on blood pressure, ketoconazole was started as a preferred option in our pediatric patient. A retrospective multicenter study concluded that ketoconazole treatment is effective with acceptable side effects, with no fatal hepatitis and adrenal insufficiency in 5.4% of patients [3]. During ketoconazole treatment, our patient developed adrenal insufficiency; however, it is impossible to conclude whether this was solely due to ketoconazole treatment or whether an ongoing COVID-19 infection contributed to the adrenal insufficiency or whether this was caused by a phase of lower or no ACTH secretion from the tumor often seen in patients with cyclic ACTH secretion. The patient’s cyclic ACTH secretion is highly probable since her morning cortisol was slightly lower and ACTH was normal, even after being off ketoconazole treatment for 3 weeks.

When retrospectively and carefully reviewing all approaches to the diagnostic and management care of our pediatric patient, it would be essential to proceed to BIPSS before any pituitary surgery, especially when obtaining discrepant results from stimulation tests, as well as detecting a discrete pituitary lesion (≤ 6 mm) as recommended by the current guidelines [16]. This was our first experience using ketoconazole in a young child, and although this treatment was associated with very good outcomes in treating hypercortisolemia, close monitoring, and family education on signs and symptoms of adrenal insufficiency are essential to recognizing adrenal insufficiency promptly in any patient with EAS, especially those presenting also with some other comorbidities or stress, here COVID-19 infection.

In conclusion, the pediatric patient here presenting with EAS caused by thymic NET needs very careful assessment including whether cyclic CS is present, the outline of a good management plan to use all tests appropriately and in the correct sequence, monitoring carefully for any signs or symptoms of adrenal insufficiency, and apply appropriate imaging studies, with experienced radiologists providing accurate readings. Furthermore, ketoconazole treatment was found to be effective in reducing the symptoms and signs of CS in this pediatric patient. Finally, due to the rarity of this disease and the challenging work-up, we suggest that a multidisciplinary team of experienced physicians in CS management is highly recommended.

Data availability

No datasets were generated or analysed during the current study.

Abbreviations

ACTH:
Adrenocorticotrophic hormone
BIPSS:
Bilateral inferior petrosal sinus sampling
CD:
Cushing disease
CRH:
Corticotropin-releasing hormone
CS:
Cushing syndrome
CT:
Computed tomography
DST:
Dexamethasone suppression test
EAS:
Ectopic adrenocorticotropic hormone syndrome
18F-FDG PET:
Fluorine-18 fluorodeoxyglucose positron emission tomography
HDDST:
High-dose dexamethasone suppression test
IV:
Intravenous
LDDST:
Low-dose dexamethasone suppression test
NET:
Neuroendocrine tumor
PitNET:
Pituitary neuroendocrine tumor
UFC:
Urinary free cortisol

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Acknowledgements

The authors thank all the colleagues from the Thomayer University Hospital and Military University Hospital who were involved in the inpatient care of this patient.

Funding

This work was supported by the Charles University research program Cooperatio Pediatrics, Charles University, Third Faculty of Medicine, Prague.

Author information

Authors and Affiliations

  1. Department of Children and Adolescents, Third Faculty of Medicine, Charles University, University Hospital Kralovske Vinohrady, Šrobárova 50, Prague, 100 34, Czech Republic

    Irena Aldhoon-Hainerová

  2. Department of Pediatrics, Thomayer University Hospital, Prague, Czech Republic

    Irena Aldhoon-Hainerová

  3. Department of Medicine, Military University Hospital, Prague, Czech Republic

    Mikuláš Kosák

  4. Third Department of Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic

    Michal Kršek

  5. Institute of Nuclear Medicine, First Faculty of Medicine, Charles University, General University Hospital, Prague, Czech Republic

    David Zogala

  6. Developmental Endocrinology, Metabolism, Genetics and Endocrine Oncology Affinity Group, Eunice Kennedy Shriver NICHD, NIH, Bethesda, MD, USA

    Karel Pacak

Contributions

All authors made individual contributions to the authorship. IAH, MK, MK, and DZ were involved in the diagnosis and management of this patient. DZ was responsible for the patient´s imaging studies. IAH wrote the first draft of the manuscript. KP revised the manuscript critically. All authors reviewed and approved the final draft.

Corresponding author

Correspondence to Irena Aldhoon-Hainerová.

Ethics declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Signed informed consent was obtained from the patient and the patient´s parents for the publication of this case report and accompanying images.

Competing interests

The authors declare no competing interests.

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Rare Challenges in Diagnosing Cushing’s Syndrome and Primary Aldosteronism: A Case Report of a Female With a Negative Workup

Posted on September 18, 2023 by MaryO

Abstract

Cushing’s syndrome with concurrent primary aldosteronism (PA) is a rare presentation, and establishing an early diagnosis is imperative to preventing morbidity and long-term sequelae. The diagnosis is established by sequential lab work, showing an elevated cortisol and aldosterone level.

Taking the above into consideration, it is evident that repeatedly negative results on all three tests can present an extremely challenging case. In this report, we discuss a female who presented with an adrenal incidentaloma and features suggestive of primary hyperaldosteronism as well as Cushing’s syndrome but no elevations in serum, urine, or salivary cortisol.

In this study, we present a 37-year-old female with resistant hypertension and tachycardia. She had several features suggestive of Cushing’s syndrome including resistant hypertension, proximal muscle weakness, weight gain, easy bruising, hair loss, and a history of tachycardia and chest pain. Examination revealed an obese female with thin silvery abdominal striae. The patient’s labs revealed normal serum cortisol, urine-free cortisol (UFC), late-night salivary cortisol, and a normal dexamethasone suppression test. An abdominal computed tomography (CT) scan revealed a right adrenal mass measuring 2.1 x 1.5 x 2.5 cm. Due to a high index of suspicion, adrenal venous sampling was performed, which revealed high levels of cortisol and aldosterone in the right vein, confirming the diagnosis. The patient subsequently underwent a right adrenalectomy. She developed hypotension post-op, leading to the diagnosis of glucocorticoid-remediable aldosteronism.

Introduction

Primary aldosteronism (PA) is the excess production of aldosterone by the adrenal glands, despite a low serum renin level. The presentation of hyperaldosteronism can be vague and include symptoms such as muscle weakness, fatigue, headaches, numbness, and cramps. More specific findings include resistant hypertension, low serum potassium, and metabolic alkalosis. The etiologies are variable and can include an adrenal adenoma (Conn syndrome) or bilateral adrenal hyperplasia [1].

Cushing’s syndrome is also caused by excess hormone secretion by the adrenal glands. The etiologies include a primary adrenal adenoma, hyperplasia, carcinoma, or exogenous corticosteroid use. It can also be caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma or as a result of paraneoplastic ACTH secretion. The clinical presentation is highly variable and leads to difficulties in establishing a diagnosis.

The concurrent existence of primary hyperaldosteronism and Cushing’s syndrome creates additional hindrances in diagnosis, yet further obscured in a patient with a repeatedly negative workup for both conditions.

Case Presentation

A 37-year-old female presented to her primary care physician with complaints of proximal muscle weakness, tachycardia, and chest pain. Repeated blood pressure readings revealed that she was hypertensive, and she was started on amlodipine and benazepril, which elevated her blood pressure further. A computed tomography (CT) scan (Figure 1) of the abdomen was performed due to resistant hypertension, which revealed an adrenal incidentaloma (right adrenal gland measuring 2.1 x 1.5 x 2.5 cm). Precontract density was 5 Hounsfield units, and a 15-minute delayed washout showed 11 Hounsfield units for a 72% washout. She was thus referred to endocrinology.

Abdominal-CT-scan-showing-a-nodule-in-the-right-adrenal-gland-measuring-2.1-x-1.5-x-2.5-cm
Figure 1: Abdominal CT scan showing a nodule in the right adrenal gland measuring 2.1 x 1.5 x 2.5 cm

She presented to the endocrinology clinic on March 12, 2021. A thorough physical examination was performed, which revealed a well-appearing obese female (BMI of 38.86 kg/m2) with no acute distress. Her blood pressure was 144/108 mmHg, her pulse was 95, and she was afebrile. Thin silvery striations were present on the abdomen, and alopecia was present on the crown. A review of all other systems was unremarkable. A detailed family history revealed early-onset hypertension in her brother (age: 35 years) and her mother (age: 30 years). Personal history included elevated anxiety, weight gain, headaches (frontal band distribution), increased thirst, easy bruising as well as delayed clearance of bruises, and proximal muscle weakness presenting as difficulty in climbing stairs and inability to lift heavy objects. She reported no change in menstrual cycles. There was no history of exogenous corticosteroid use.

Serum biochemistries were sent (Table 1), which showed normal levels of thyroid stimulating hormone (TSH), creatinine, liver function tests, and serum electrolytes. However, mildly elevated aldosterone (23 ng/dl), mild hypokalemia (3.3 mEq/L), and suppressed ACTH and dehydroepiandrosterone (DHEA) sulfate were discovered. The aldosterone to renin ratio was also elevated at 59.9 on spironolactone and was 71.4 three months later when spironolactone was discontinued. These findings lead to a preliminary diagnosis of primary hyperaldosteronism.

Test Result
Calcium 9.1 mmol/L
Sodium 137 mmol/L
Potassium 4.1 mmol/L
Chloride 106 mmol/L
CO2 27
BUN 15 mmol/L
Glucose 95 mmol/L
Creatinine 1.1 μmol/L
AST 24 U/L
ALT 20 U/L
Albumin 4.4 g/L
Total protein 7.0 g/L
Total bilirubin 0.4 μmol/L
Alkaline phosphatase 40 U/L
Renin 0.44
Table 1: Patient serum biochemistries

BUN: Blood urea nitrogen; AST: Aspartate transaminase; ALT: Alanine transaminase.

A workup for elevated cortisol was also performed as the patient was phenotypically Cushingoid, and the following biochemistries were sent sequentially: serum cortisol, 24-hour urine-free cortisol (UFC), salivary cortisol, and a low-dose dexamethasone suppression test (Table 2). The bloodwork was hence nonconfirmatory.

Endocrine workup
Serum cortisol 4.5 mcg/dL
Urine-free cortisol 1.57 g/24 h
Salivary cortisol <0.03 μg/dL
Dexamethasone suppression test 1.5 mcg/dL
Aldosterone <4.0
Table 2: Patient follow-up bloodwork

Despite a repeatedly negative workup for Cushing’s syndrome, adrenal venous sampling was performed due to a high index of suspicion. The results revealed an inferior vena cava (IVC) cortisol of 20, left adrenal venous (LAV) cortisol of 81, and right adrenal vein (RAV) cortisol of 1280. The results of the IVC aldosterone were 24, LAV aldosterone was 660 and RAV aldosterone was 1500. The elevated levels of cortisol in the RAV were in complete contradiction to the aforementioned workup. A diagnosis of Cushing’s syndrome and concurrent PA was determined.

Adrenal veinous sampling was instrumental in establishing the diagnosis but was equivocal and did not lateralize aldosterone and cortisol excess. However, the amount of aldosterone and cortisol were both significantly higher on the right side. After a panel discussion with doctors from several disciplines, a laparoscopic adrenalectomy was planned. The procedure was successful, and the patient was initially showing clinical improvement. The specimen was sent for pathological evaluation and revealed an adrenal cortical adenoma.

After initial improvement, the patient developed hypotension, which was likely due to adrenal insufficiency. The patient was supplemented with 1-mg dexamethasone tablets, which stabilized her condition, and a diagnosis of glucocorticoid-remediable-aldosteronism was made.

Based on a strong family history of early onset-resistant hypertension, a genetic component was suspected. Several genes associated with PA with autosomal dominant inheritance have been identified [2], such as CYP11B2, CLCN2, KCNJ5, CACNA1D, and CACNA1H. The patient was offered genetic testing but was unable to follow through due to financial reasons.

Discussion

This patient presented as an extremely rare example of PA and Cushing’s syndrome, with negative serum cortisol, 24-hour UFC, late-night salivary cortisol, and a dexamethasone suppression test. Despite repeatedly negative lab results, the patient presented with a markedly elevated cortisol on adrenal venous sampling. In our literature search, we found an instance of a patient with several negative UFCs [3]; however, to the best of our knowledge, there have been no reported instances of a completely negative workup in a patient who is positive for Cushing’s syndrome. In fact, in the practice guidelines published by the Journal of Clinical Endocrinology & Metabolism [4], it is recommended that patients with a suspected diagnosis of Cushing’s syndrome or an adrenal incidentaloma and two concordant negative test results need not undergo further investigations.

One proposed mechanism for the misleading workup could be assay interference. Interference occurs when a substance or process falsely alters an assay result [5]. This can lead to incorrect diagnosis and subsequent treatment and poses a threat to the patient. Another suggested mechanism causing false negative test results could be the hook effect [6]. The hook effect is described as a phenomenon that leads to falsely low results due to the presence of excessive analyte.

In a study by Friedman et al. [7], it was noted that patients with “episodic Cushing’s syndrome” or those with mild symptoms had a negative workup. The study recommended serial monitoring for the disease. The interesting fact is that our patient had several features suggestive of active Cushing’s syndrome, and the hypotension seen postoperatively was a testament to the fact that there was in fact a cortisol excess, which led to adrenal insufficiency. In light of the above, a consistently negative workup is perplexing.

Zhang et al. suggested performing a low-dose dexamethasone suppression test in individuals presenting with PA, prior to adrenal vein sampling (AVS) and surgery due to the high prevalence of Cushing’s syndrome in patients with PA [8]. A positive test result can lead to a straightforward diagnosis; however, in this rare case where the patient had severe negative tests, it can present as a challenge in diagnosis and treatment.

Conclusions

The presence of PA and concurrent Cushing’s syndrome can present as a diagnostic challenge. It is recommended to follow up on the signs of Cushing’s syndrome with preliminary tests and to presume its absence if two concordant tests are negative. Our patient, however, was an exceptional case.

This case highlighted the importance of maintaining a high index of suspicion for patients presenting with several signs and symptoms of the disease and a negative workup. More attention should be paid to the patient’s history, and a thorough physical examination should be conducted. In those with an uncertain diagnosis, adrenal venous sampling can provide a clearer picture and lead to a more accurate understanding of the case.

References

  1. Reincke M, Bancos I, Mulatero P, Scholl UI, Stowasser M, Williams TA: Diagnosis and treatment of primary aldosteronism. Lancet Diabetes Endocrinol. 2021, 9:876-92. 10.1016/S2213-8587(21)00210-2
  2. Dutta RK, Söderkvist P, Gimm O: Genetics of primary hyperaldosteronism. Endocr Relat Cancer. 2016, 23:R437-54. 10.1530/ERC-16-0055
  3. Moloney KJ, Mercado JU, Ludlam WH, Broyles FE: Diagnosis of Cushing’s disease in a patient with consistently normal urinary free cortisol levels: a case report. Clin Case Rep. 2016, 4:1181-3. 10.1002/ccr3.647
  4. Nieman LK, Biller BM, Findling JW, Newell-Price J, Savage MO, Stewart PM, Montori VM: The diagnosis of Cushing’s syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008, 93:1526-40. 10.1210/jc.2008-0125
  5. Dimeski G: Interference testing. Clin Biochem Rev. 2008, 29:S43-8.
  6. The hook effect. (2014). Accessed: June 19, 2023: https://www.aacc.org/science-and-research/clinical-chemistry-trainee-council/trainee-council-in-english/pearls-of-lab….
  7. Friedman TC, Ghods DE, Shahinian HK, et al.: High prevalence of normal tests assessing hypercortisolism in subjects with mild and episodic Cushing’s syndrome suggests that the paradigm for diagnosis and exclusion of Cushing’s syndrome requires multiple testing. Horm Metab Res. 2010, 42:874-81. 10.1055/s-0030-1263128
  8. Zhang Y, Tan J, Yang Q, et al.: Primary aldosteronism concurrent with subclinical Cushing’s syndrome: a case report and review of the literature. J Med Case Rep. 2020, 14:32. 10.1186/s13256-020-2353-8

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Cushing’s Syndrome, Prostate Cancer and Adrenocortical Carcinoma

Posted on March 11, 2013 by MaryO

Orphagen has identified and characterized small molecule antagonists to steroidogenic factor-1 (SF-1). SF-1 binds to and regulates DNA promoter elements in the major transporters and enzymes required for adrenal steroid synthesis. It is also required for development of the adrenal gland. SF-1 antagonists inhibit cortisol secretion in adrenal cells and have potential application in two orphan indications, Cushing’s syndrome and adrenocortical carcinoma. In addition, SF-1 appears to have an important role in the progression of advanced prostate cancer.

 

cushings-adrenocortical-crop

 

Cushing’s syndrome:
An estimated 20,000 people in the US have Cushing’s, with more than 3,000 new cases diagnosed each year. The incidence is similar in Europe. Cushing’s syndrome disproportionately affects females, who make up about 75% of the diagnosed cases. Symptoms of Cushing’s syndrome can include obesity, diabetes, psychiatric disorders, osteoporosis and immune suppression. Cushing’s syndrome is caused by elevated secretion of cortisol from the adrenal gland, in association with pituitary, adrenal or other cancers.

Orphagen has identified small molecule antagonists to SF-1 that have the potential to suppress cortisol levels in all Cushing’s patients without serious side effects.

Adrenocortical carcinoma (ACC):
ACC is a rare malignancy with an extremely poor prognosis (5-year overall survival: 37-47%). Complete surgical resection offers hope for long-term survival but surgery is not an option in up to two-thirds of patients because metastasis has usually occurred by the time of diagnosis.

SF-1 is recognized as a potential mechanism-based therapeutic target for control of ACC and an SF-1 antagonist could be used in the treatment of ACC.

Pediatric ACC:
Pediatric ACC is a very rare but aggressive cancer with a long-term survival rate of about 50%. Approximately 60% of children with adrenocortical tumors are diagnosed before the age of four. The SF-1 gene is amplified and SF-1 protein is overexpressed in the vast majority of childhood adrenocortical tumors strongly implicating SF-1 in pediatric adrenocortical tumorigenesis.

Castration resistant prostate cancer (CRPC):
CRPC is the most common cancer in males. Surgery is not an option if the cancer has spread beyond the prostate gland, at which point patients typically receive hormonal therapy, essentially chemical castration. This course of therapy usually fails within two years, resulting in castration resistant prostate cancer (CRPC). Most patients eventually succumb to CRPC, which is the second leading cause of cancer deaths in men.
SF-1 antagonists may: (1) block the adrenal androgens that circumvent chemical castration, and are a primary cause of CRPC; and (2) inhibit synthesis of androgens within the prostate tumor itself, where SF-1 may control induction of enzymes for de novo androgen synthesis in treatment-resistant cancers.

From http://www.orphagen.com/research_cushings.html

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