Algorithm for evaluation of an incidentally detected adrenal mass. (1) Consider biochemical assays to determine functional status and exclude pheochromocytoma before biopsy/resection. (2) “No enhancement” applies if an examination without and with intravenous contrast is available. (3) “Isolated” defined as no other metastatic disease identified. (4) May consider chemical-shift MRI (CS-MR). APW = absolute percentage washout; Ca++ = calcification; F/U = follow-up; HU = Hounsfield units; Hx = history; NCCT = CT without intravenous contrast; RPW = relative percentage washout; + = positive.