Adrenal myelolipoma(s) as presenting manifestation of subclinical Cushing's disease (eutopic ACTH-dependent Cushing's syndrome).

Primary adrenal myelolipomas, relatively rare benign tumours of the adrenal cortex are typically unilateral, hormonally inactive and asymptomatic, hence often diagnosed as 'adrenal incidentaloma'. Bilateral adrenal myelolipomas, in particular, may be associated with underlying endocrinopathies associated with elevated circulating adrenocorticotropic hormone (ACTH) concentration. Subclinical cortisol hypersecretion, irrespective of its ACTH dependency, does not manifest typical clinical phenotype of hypercortisolemia, and thus termed subclinical Cushing's syndrome. In this article, hormonal evaluation in a middle-aged woman with diabetes, hypertension and incidentally discovered unilateral adrenal myelolipoma revealed underlying subclinical Cushing's disease. Abdominal CT revealed another tiny focus in the contralateral adrenal gland, probably representing incipient myelolipoma.