[131I]iodocholesterol scintiscan and a rare "functional" black adenoma of the adrenal cortex

A rare functional black adenoma (FBA) of the adrenal cortex was found to be the cause of hypertension and cushingold features in a 34-yr-old white female. Preoperative studies included [131I]iodocholesterol scanning (ICS) of the adrenal glands, which demonstrated the increased release of cortisol from the affected adrenal gland, with the failure of the opposite adrenal gland to record. This is evidence that cortisol was suppressing adrenocorticotropin (ACTH) output by the pituitary gland. This case documents the clinical utility of "functional" imaging techniques in this clinical setting.