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Adrenocorticotropic hormone-independent bilateral macronodular adrenocortical hyperplasia associated with Cushing's
J Irie1, K Kawai, K Shigematsu
1Department of Pathology, Nagasaki Prefectural Adult Disease Center, Tarami Hospital, Japan.
Insights
Adrenocorticotropic hormone independent bilateral adrenocortical macronodular hyperplasia (AIMAH) can cause Cushing's syndrome. Pathologists should consider AIMAH when diagnosing adrenal disorders.
Area of Science:
- Endocrinology
- Pathology
- Oncology
Background:
- Adrenocorticotropic hormone independent bilateral adrenocortical macronodular hyperplasia (AIMAH) is a rare cause of Cushing's syndrome.
- This condition is characterized by bilateral adrenal enlargement without elevated adrenocorticotropic hormone (ACTH) levels.
Observation:
- A 59-year-old male presented with hypertension, leading to the discovery of hypercortisolism.
- Diagnostic workup revealed low plasma ACTH, loss of diurnal ACTH rhythm, and lack of suppression with high-dose dexamethasone.
- Abdominal imaging confirmed bilateral adrenal enlargement with nodular changes.
Findings:
- Histopathological examination of the adrenal glands showed a variegated pattern with zona glomerulosa-like (ZG-like) structures.
- Immunohistochemical analysis revealed specific enzyme expressions (cytochrome P-450 17 alpha positive, 3 beta-HSD negative) in the ZG-like cells.
- Ultrastructural studies indicated similarity between ZG-like cells and normal zona glomerulosa cells.
Implications:
- AIMAH is a distinct clinicopathological entity contributing to Cushing's syndrome.
- Pathologists should include AIMAH in the differential diagnosis for adrenal hyperplasia in patients with Cushing's syndrome.
- Accurate diagnosis of AIMAH is crucial for appropriate patient management and treatment strategies.
Abstract:
A case of adrenocorticotropic hormone independent bilateral adrenocortical macronodular hyperplasia (AIMAH) is reported. A 59 year old male was admitted to hospital because of hypertension. Subsequently, hypercortisolism, low plasma adrenocorticotropic hormone (ACTH), loss of diurnal rhythm of ACTH, lack of suppression with high dose dexamethasone were found and bilateral adrenal enlargement was detected by abdominal computerized tomography and adrenal scintigraphy. Bilateral total adrenalectomy was performed under a diagnosis of bilateral adrenal hyperplasia associated with Cushing's syndrome. Both adrenal glands were enlarged in size and weight. Bulging nodules were found at the cut section. Microscopically, a variegated histologic pattern including trabecular, adenoid and zona glomerulosa-like (ZG-like) structures was revealed in the nodules. Immunohistochemical examination disclosed positive staining of cytochrome P-450 17 alpha, negative of 3 beta-HSD in the ZG-like structure. Ultrastructurally, the cells composing the ZG-like structure were similar to those of the ZG in normal adrenal cortex. The authors agree that AIMAH is one of the entities causing Cushing's syndrome, and advise pathologists to keep this disorder in mind when they examine the adrenals in Cushing's syndrome.