ACTH-independent macronodular adrenal hyperplasia: imaging findings of a rare condition—a case report

Abstract: Endogenous Cushing’s syndrome is a relatively rare disease. Most cases being ACTH-dependent. ACTH-independent Cushing’s syndrome (AICS) is an even rarer condition (15%–20%). In more than 95% cases, the cause of AICS is unilateral adrenal enlargement caused by adenoma or carcinoma. Bilateral adrenal disease is caused by primary pigmented nodular adrenal dysplasia (PPNAD) and ACTH-independent macronodular hyperplasia (AIMAH). Only a few case reports of the latter condition exist in the radiology literature, PPNAD being the commoner of two as the cause for AICS.