Case Report: Three Rare Cases of Ectopic ACTH Syndrome Caused by Adrenal Medullary Hyperplasia

Ectopic ACTH syndrome (EAS) accounts for 10–20% of endogenous Cushing’s syndrome (CS). Hardly any cases of adrenal medullary hyperplasia have been reported to ectopically secrete adrenocorticotropic hormone (ACTH). Here we describe a series of three patients with hypercortisolism secondary to ectopic production of ACTH from adrenal medulla. Cushingoid features were absent in case 1 but evident in the other two cases. Marked hypokalemia was found in all three patients, but hyperglycemia and osteoporosis were present only in case 2. All three patients showed significantly elevated serum cortisol and 24-h urinary cortisol levels. The ACTH levels ranged from 19.8 to 103.0pmol/L, favoring ACTH-dependent Cushing’s syndrome. Results of bilateral inferior petrosal sinus sampling (BIPSS) for case 1 and case 3 confirmed ectopic origin of ACTH. The extremely high level of ACTH and failure to suppress cortisol with high dose dexamethasone suppression test (HDDST) suggested EAS for patient 2. However, image studies failed to identify the source of ACTH secretion. Bilateral adrenalectomy was performed for rapid control of hypercortisolism. After surgery, cushingoid features gradually disappeared for case 2 and case 3. Blood pressure, blood glucose and potassium levels returned to normal ranges without medication for case 2. The level of serum potassium also normalized without any supplementation for case 1 and case 3. The ACTH levels of all three patients significantly decreased 3-6 months after surgery. Histopathology revealed bilateral adrenal medullary hyperplasia and immunostaining showed positive ACTH staining located in adrenal medulla cells. In summary, our case series reveals the adrenal medulla to be a site of ectopic ACTH secretion. Adrenal medulla-originated EAS makes the differential diagnosis of ACTH-dependent Cushing’s syndrome much more difficult. Control of the hypercortisolism is mandatory for such patients.

Adrenal medullary hyperplasia mimicking pheochromocytoma

A 59-year-old woman, a known case of hypertension, was incidentally diagnosed with a large right-sided adrenal mass. Investigations for a functional adrenal lesion resulted in very high preoperative norepinephrine levels. A right adrenalectomy was performed. Histology showed adrenal medullary hyperplasia (AMH). AMH is a rare diagnosis and its incidence is poorly documented in the literature. This is a benign entity which resembles pheochromocytoma (PCC) in both clinical and biochemical manner. AMH is usually bilateral and may occur in isolation or in association with PCC. In fact, some authors consider it to be a precursor to PCC. Thus, these patients need long-term follow-up in view of the risk of development of PCC later.

Presentation, Treatment, Histology, and Outcomes in Adrenal Medullary Hyperplasia Compared With Pheochromocytoma

Context Information about adrenal medullary hyperplasia (AMH) is scarce. Objective To study a large cohort of AMHs. Design, Setting, and Participants Nineteen AMH cases were compared with 95 pheochromocytomas (PCCs) without AMH. AMH without (n = 7) and with PCC (n = 12) were analyzed separately. Results Of 936 adrenalectomies, 2.1% had AMH. Mean age was 47.2 ± 15.1 years. Only two (11%) AMHs had no concurrent PCC or adrenocortical adenoma. In AMHs, a genetic syndrome was present in 58% vs 4% in PCCs (P < 0.001). The noradrenaline/metanephrine levels were lower in AMHs, whereas suppression of dexamethasone was less than in PCCs. Cushing syndrome was found in 11% of AMHs. More AMHs were found during screening and less as incidentalomas. PCC symptoms were less prevalent in AMHs. Surgical management was similar; however, fewer of the AMHs were pretreated with alpha-blockers. Adrenalectomy improved blood pressure slightly less in AMHs. The disappearance of glycemic disturbances was similar to the PPCs. During a period of 11.2 ± 9.4 years, a new PCC developed in 32% of patients with AMH, 11% died, but no PCC metastasis occurred (PCCs: 4%, P < 0.001; 14% and 5%). AMHs without PCC had milder symptoms but more often Cushing disease than patients with PCC, whereas AMH with PCC more often displayed a familiar syndrome with more PCC recurrences. Conclusion A total of 2.1% of all adrenalectomies displayed AMH. AMH seemed to be a PCC precursor. The symptoms and signs were milder than PCCs. AMHs were mainly found due to screening. Outcomes seemed favorable, but new PCCs developed in many during follow-up.