Ectopic adrenal adenoma

CT image of a 45-year-old female with ACTH-independent Cushing's syndrome. A 3 x 3 cm mass, which is a benign ectopic adrenal adenoma, is noted near the left renal pelvis (arrow). This patient had undergone previous bilateral adrenalectomy in the mistaken belief that she had bilateral adrenal micronodular hyperplasia. This was followed by 125-I cholesterol scanning on two occasions, which did not detect the ectopic mass.