Bilateral macronodular adrenal hyperplasia (BMAH) is an adrenal disorder characterized by bilateral benign adrenocortical nodules associated with variable levels of cortisol excess. BMAH is an adrenal cause of Cushing's syndrome (CS). An increased activity of the cAMP/PKA pathway is found in the various forms of BMAH. Actors of the cAMP/PKA signaling pathway or genes causing a hereditary familial tumor syndrome including adenomatous polyposis coli gene (APC), menin (MEN1) and fumarate hydratase (FH) can favor or be responsible for the development of BMAH. Recently, a new gene, ARMC5, was identified as a frequent cause of sporadic or familial BMAH.
