Ectopic pro-opiomelanocortin syndrome

Ectopic pro-opiomelanocortin (POMC) syndrome remains one of the most challenging differential diagnoses in clinical endocrinology. In an attempt to revisit recent basic and clinical advances in the diagnosis of ectopic POMC syndrome, we undertook an extensive literature review of 530 cases in 197 published papers to provide a molecular biologic, demographic, and diagnostic update. Subgroup analysis of patients with ectopic POMC syndrome reveals a broad spectrum of severity and progression of signs and symptoms of hypercortisolism. The endocrine work-up of a patient with suspected ectopic POMC syndrome includes the establishment of pathologic hypercortisolism, diagnosis of adrenocorticotropic hormone (ACTH) dependency, and lastly, the differential diagnosis of ACTH-dependent Cushing's syndrome. Diagnostic imaging, including conventional radiologic techniques and somatostatin receptor scintigraphy, are helpful in the correct localization and eventual treatment of ectopic POMC production.