Pseudo-pheochromocytoma due to obstructive sleep apnea: a case report

SUMMARY

Obstructive sleep apnea (OSA) is a condition of intermittent nocturnal upper airway obstruction. OSA increases sympathetic drive which may result in clinical and biochemical features suggestive of pheochromocytoma. We present the case of a 65-year-old male with a 2.9-cm left adrenal incidentaloma on CT, hypertension, symptoms of headache, anxiety and diaphoresis, and persistently elevated 24-h urine norepinephrine (initially 818 nmol/day (89-470)) and normetanephrine (initially 11.2 µmol/day (0.6-2.7)). He was started on prazosin and underwent left adrenalectomy. Pathology revealed an adrenal corticoadenoma with no evidence of pheochromocytoma. Over the next 2 years, urine norepinephrine and normetanephrine remained significantly elevated with no MIBG avid disease. Years later, he was diagnosed with severe OSA and treated with continuous positive airway pressure. Urine testing done once OSA was well controlled revealed complete normalization of urine norepinephrine and normetanephrine with substantial symptom improvement. It was concluded that the patient never had a pheochromocytoma but rather an adrenal adenoma with biochemistry and symptoms suggestive of pheochromocytoma due to untreated severe OSA. Pseudo-pheochromocytoma is a rare presentation of OSA and should be considered on the differential of elevated urine catecholamines and metanephrines in the right clinical setting.

LEARNING POINTS

Obstructive sleep apnea (OSA) is a common condition among adults. OSA may rarely present as pseudo-pheochromocytoma with symptoms of pallor, palpitations, perspiration, headache, or anxiety. OSA should be considered on the differential of elevated urine catecholamines and metanephrines, especially in patients with negative metaiodobenzylguanidine (MIBG) scan results.

Risk of bone fractures after the diagnosis of adrenal adenomas: a population-based cohort study

OBJECTIVE

Several small studies reported increased prevalence and incidence of asymptomatic vertebral fractures in patients with non-functioning adrenal adenomas and adenomas with mild autonomous cortisol secretion. However, the risk of symptomatic fractures at vertebrae, and at other sites remains unknown. Our objective was to determine the prevalence and incidence of symptomatic site-specific fractures in patients with adrenal adenomas.

DESIGN

Population-based cohort study, Olmsted County, Minnesota, USA, 1995-2017.

METHODS

Participants were the patients with adrenal adenoma and age/sex-matched referent subjects. Patients with overt hormone excess were excluded. Main outcomes measures were prevalence and incidence of bone fractures.

RESULTS

Of 1004 patients with adrenal adenomas, 582 (58%) were women, and median age at diagnosis was 63 years (20-96). At the time of diagnosis, patients had a higher prevalence of previous fractures than referent subjects (any fracture: 47.9% vs 41.3%, P = 0.003, vertebral fracture: 6.4% vs 3.6%, P = 0.004, combined osteoporotic sites: 16.6% vs 13.3%, P = 0.04). Median duration of follow-up was 6.8 years (range: 0-21.9 years). After adjusting for age, sex, BMI, tobacco use, prior history of fracture, and common causes of secondary osteoporosis, patients with adenoma had hazard ratio of 1.27 (95% CI: 1.07-1.52) for developing a new fracture during follow up when compared to referent subjects.

CONCLUSIONS

Patients with adrenal adenomas have higher prevalence of fractures at the time of diagnosis and increased risk to develop new fractures when compared to referent subjects.

Low Diagnostic Utility of Overnight High-Dose Dexamethasone Suppression Test in ACTH-Dependent Cushing's Syndrome

OBJECTIVE

Overnight high-dose dexamethasone suppression test (ON-HDDST) is a simple test to localize the source of ACTH in patients with ACTH-dependent Cushing's syndrome (CS). However, previous studies have reported its varying accuracy. We studied the utility of ON-HDDST in diagnosing Cushing's disease (CD) in a series of patients with CD and ectopic ACTH syndrome (EAS).

METHODS

We conducted a retrospective study of 88 patients with ACTH-dependent CS (plasma ACTH > 20.0 pg/mL), who underwent an ON-HDDST. CD and EAS were diagnosed in 68 and 20 patients, respectively. Patients were investigated using MRI of the sellar region, CT of the thorax/abdomen, Gallium-68-DOTANOC PET scan, and bilateral inferior petrosal sinus sampling as required.

RESULTS

Patients with EAS had a significantly higher serum cortisol after ON-HDDST than patients with CD (median [IQR], 19.9 [12.4-31.1] μg/dL vs 9.9 [5.1-25.0] μg/dL, P <.01). A suppressed ON-HDDST (≥50% fall from baseline) was noted in 44 (65%) patients with CD and 3 (15%) patients with EAS (P <.0001). Among patients with CD, cortisol suppression >50% was noted in 35 (76%) of patients with microadenoma and 7 (44%) with macroadenoma. Among patients with EAS, ON-HDDST was suppressed in 1 of 6 patients (17%) with an occult tumor and 2 of 14 patients (14%) with a localized tumor. The ROC curve plotted for the percentage suppression of cortisol had an area under the curve (AUC) of 0.72 (P =.01). The best test parameters, with 65% sensitivity, 85% specificity, 94% positive predictive value, 42% negative predictive value, and 69% accuracy, were at 50% cutoff level.

CONCLUSION

The ON-HDDST had a poor diagnostic value in differentiating CD and EAS.

A case of renovascular hypertension with incidental primary bilateral macronodular adrenocortical hyperplasia

SUMMARY

Renovascular hypertension (RVHT) is an important and potentially treatable form of resistant hypertension. Hypercortisolemia could also cause hypertension and diabetes mellitus. We experienced a case wherein adrenalectomy markedly improved blood pressure and plasma glucose levels in a patient with RVHT and low-level autonomous cortisol secretion. A 62-year-old Japanese man had been treated for hypertension and diabetes mellitus for 10 years. He was hospitalized because of a disturbance in consciousness. His blood pressure (BP) was 236/118 mmHg, pulse rate was 132 beats/min, and plasma glucose level was 712 mg/dL. Abdominal CT scanning revealed the presence of bilateral adrenal masses and left atrophic kidney. Abdominal magnetic resonance angiography demonstrated marked stenosis of the left main renal artery. The patient was subsequently diagnosed with atherosclerotic RVHT with left renal artery stenosis. His left adrenal lobular mass was over 40 mm and it was clinically suspected the potential for cortisol overproduction. Therefore, laparoscopic left nephrectomy and adrenalectomy were simultaneously performed, resulting in improved BP and glucose levels. Pathological studies revealed the presence of multiple cortisol-producing adrenal nodules and aldosterone-producing cell clusters in the adjacent left adrenal cortex. In the present case, the activated renin-angiotensin-aldosterone system and cortisol overproduction resulted in severe hypertension, which was managed with simultaneous unilateral nephrectomy and adrenalectomy.

LEARNING POINTS

Concomitant activation of the renin-angiotensin-aldosterone system and cortisol overproduction may contribute to the development of severe hypertension and lead to lethal cardiovascular complications. Treatment with simultaneous unilateral nephrectomy and adrenalectomy markedly improves BP and blood glucose levels. CYP11B2 immunohistochemistry staining revealed the existence of aldosterone-producing cell clusters (APCCs) in the adjacent non-nodular adrenal gland, suggesting that APCCs may contribute to aldosterone overproduction in patients with RVHT.

Acromegaly remission, SIADH and pituitary function recovery after macroadenoma apoplexy

Summary

Pituitary apoplexy is a rare but potentially life-threatening clinical syndrome characterised by ischaemic infarction or haemorrhage into a pituitary tumour that can lead to spontaneous remission of hormonal hypersecretion. We report the case of a 50-year-old man who attended the emergency department for sudden onset of headache. A computed tomography (CT) scan at admission revealed pituitary haemorrhage and the blood test confirmed the clinical suspicion of acromegaly and an associated hypopituitarism. The T1-weighted magnetic resonance imaging (MRI) showed the classic pituitary ring sign on the right side of the pituitary. Following admission, he developed acute-onset hyponatraemia that required hypertonic saline administration, improving progressively. Surprisingly, during the follow-up, IGF1 levels became normal and he progressively recovered pituitary function.

Learning Points

Patients with pituitary apoplexy may have spontaneous remission of hormonal hypersecretion. If it is not an emergency, we should delay a decision to undertake surgery following apoplexy and re-evaluate hormone secretion. Hyponatraemia is an acute sign of hypocortisolism in pituitary apoplexy. However, SIADH although uncommon, could appear later as a consequence of direct hypothalamic insult and requires active and individualised treatment. For this reason, closely monitoring sodium at the beginning of the episode and throughout the first week is advisable to guard against SIADH. Despite being less frequent, if pituitary apoplexy is limited to the tumour, the patient can recover pituitary function previously damaged by the undiagnosed macroadenoma.

Cyclic Subclinical Hypercortisolism: A Previously Unidentified Hypersecretory Form of Adrenal Incidentalomas

Purpose

Most adrenal incidentalomas (AIs) are nonfunctioning adenomas (NFAs), but up to 30% may secrete cortisol autonomously without clinical evidence of Cushing syndrome (CS), which nevertheless may increase cardiovascular mortality. This subclinical hypercortisolism (SCH) is confirmed by cortisol resistance to a dexamethasone suppression test (DST). Cyclic cortisol secretion occurs in classic CS but was not reported in SCH.

Objective

Investigate cyclic cortisol production/autonomy in AIs using sequential DSTs.

Methods

A total of 251 patients with AI underwent 487 DSTs over 12 years; patients with at least three DSTs were selected. DSTs were validated by measuring serum dexamethasone. Cyclic SCH was defined when at least two abnormal and two normal DSTs were documented.

Results

A total of 44 patients had three or more DSTs during follow-up: 9 of 44 patients (20.4%) had all negative test results (post-DST cortisol ≤1.8 μg/dL) and were classified as NFA; another nine patients had all positive results (cortisol >1.8 μg/dL) and were classified as sustained SCH. The remaining 26 (59.2%) had discordant responses: 8 of 44 (18.3%) had at least two positive and two negative tests, matching the criterion for cyclic SCH, whereas 18 of 44 (40.9%) had only one discordant test and were classified as possibly cyclic SCH. Eleven of 20 (55%) patients initially classified as NFA did not maintain their cortisol pattern.

Conclusions

Extended follow-up with repeated DSTs uncovered an unusual subset of AIs with cyclic SCH. Recurring production of cortisol may affect determination of AI subtypes if based on just one DST. Lack of recognition of this phenomenon makes follow-up of patients with AI misleading because even cyclic SCH may result in potential cardiovascular risk.

Relationship between social rank and cortisol and testosterone concentrations in male cynomolgus monkeys (Macaca fascicularis)

In nonhuman primate social groups, biological differences related to social status have proven useful for investigating the mechanisms of sensitivity to various disease states. Physiological and neurobiological differences between dominant and subordinate monkeys have been interpreted in the context of chronic social stress. The present experiments were designed to investigate the relationships between basal cortisol and testosterone concentrations and the establishment and maintenance of the social hierarchy in male cynomolgus monkeys. Cortisol concentrations were measured at baseline and following suppression with dexamethasone (DEX) and subsequent administration of adrenocorticotrophic hormone (ACTH) while monkeys were individually housed (n = 20) and after 3 months of social housing (n = 4/group), by which time dominance hierarchies had stabilised. Cortisol was also measured during the initial 3 days of social housing. Neither pre-social housing hormone concentrations, nor hypothalamic-pituitary-adrenal (HPA) axis sensitivity predicted eventual social rank. During initial social housing, cortisol concentrations were significantly higher in monkeys that eventually became subordinate; this effect dissipated within 3 days. During the 12 weeks of social housing, aggressive and submissive behaviours were observed consistently, forming the basis for assignment of social ranks. At this time, basal testosterone and cortisol concentrations were significantly higher in dominant monkeys and, after DEX suppression, cortisol release in response to a challenge injection of ACTH was significantly greater in subordinates. These results indicate that basal cortisol and testosterone concentrations and HPA axis function are state variables that differentially reflect position in the dominance hierarchy, rather than trait variables that predict future social status.