Epinephrine-secreting cystic pheochromocytoma presenting with an incidental adrenal mass: a case report and a review of the literature.

Cystic adrenal masses are a relatively rare condition, and are usually nonfunctioning and asymptomatic. Differential diagnosis includes pheochromocytoma (PHEO) and adrenal carcinoma; 8-10% of patients with PHEO may be completely asymptomatic. Moreover, fewer than 10% of PHEOs secrete pure epinephrine. We report a case of a E-secreting pure cystic PHEO presenting with an incidental adrenal mass. A 49-year-old Turkish woman was hospitalized at Farabi Hospital for further examinations of a right adrenal cystic mass with a thick wall that was incidentally discovered by abdominal ultrasonography during examination for nausea, vomiting, headache, and angina-like chest pain in another hospital. On admission, her blood pressure was 100/60 mmHg. Tension Holter monitoring revealed paroximal hypertension (178/136 mmHg) and hypotension (78/54 mmHg) attacks. Of urinary catecholamines and its metabolites, only urine metanephrine was markedly increased, despite a urine epinephrine level near the upper limit of normal ranges. Abdominal computed tomography and magnetic resonance imaging studies revealed a cystic round tumor approx 5 cm in diameter, located in the right adrenal gland. Right adrenalectomy was performed; the surgical specimen revealed pure cystic PHEO. Postoperatively, the urine metanephrine level returned to normal range and urine epineprine level was decreased approx 60%. In conclusion, a diagnosis of E-secreting PHEO should be considered in patients with nonspecific symptoms, presenting with an incidental cystic adrenal mass, even in the absence of hypertension.