A rare case of duodenal carcinoid presenting as ectopic Cushing’s syndrome

ABSTRACT

ACTH-dependent Cushing syndrome (CS) due to an ectopic source is responsible for approximately 10-15% cases of Cushing’s syndrome. It is associated with various tumors such as small cell lung cancer and well-differentiated bronchial or gastrointestinal neuroendocrine tumors. Many a times ectopic ACTH production is difficult to manage, and identification of the source may take many years. Hormonal diagnostics include assessments in basic conditions as well as dynamic tests, such as the high-dose dexamethasone suppression test and corticotrophin releasing hormone (CRH) stimulation test. Treatment selection depends on the type of tumor and its extent. In the case of neuroendocrine tumors, the main treatments are surgery and administration of somatostatin analogues or bilateral adrenalectomy in refractory cases and if the source remains unidentified. Here, we report a case who presented with features of Cushing’s syndrome which eventually through workup led us to a diagnosis of duodenal carcinoid producing ectopic ACTH which is extremely rare and was successfully treated.