CYCLIC CUSHINGS-SYNDROME DUE TO ECTOPIC ACTH-SECRETION BY AN ADRENAL PHEOCHROMOCYTOMA

Pheochromocytoma is a rare cause of ectopic Cushing's syndrome, We rep ort on such a patient in whom ectopic ACTH secretion displayed a cycli c pattern. A 35-year-old woman was referred to us with a diagnosis of ACTH-dependent Gushing's syndrome. A 3.3 cm left-sided adrenal mass wa s noted at abdominal computerized tomography. At admission, clinical a nd hormonal data were unrewarding, so it was decided to continue to ob serve the patient. Four months later, she became symptomatic with hype rtensive and psychotic crises and glycemic decompensation. By that tim e, a full-blown Cushing picture was evident. Severe hypercortisolism w as documented with urinary free cortisol ranging 1500-2200 mu g/24 h, serum cortisol 143-160 mu g/dl and plasma ACTH 167-218 pg/ml. Neither ACTH nor cortisol values were significantly modified after high-dose d examethasone, oCRH or metyrapone. Urinary catecholamine and vanilyl ma ndelic acid excretion were moderately elevated. Chest CT and total bod y MIBG scan were negative and magnetic resonance of the sella region w as inconclusive. No center to periphery ACTH gradient was observed by inferior petrosal sinus catheterization, whereas a significant left to right gradient was found on selective adrenal vein catheterization. A left adrenalectomy was performed and a 4 cm medullary neoplasia was r emoved. The cells were immunostained for ACTH, neuron-specific enolase and A chromogranin. Signs and symptoms of Cushing's syndrome resolved with normalization of basal and dynamic endocrine evaluations. The pa tient is considered cured 10 months after surgery.