Abstract
Pheochromocytoma is a rare neuroendocrine tumor arising from adrenal medulla. Patients usually show classic triad of headache, palpitations and diaphoresis along with persistent or paroxysmal hypertension. Majority of the tumors are solid or mixed solid and cystic. But purely cystic variant is extremely rare with few cases reports available in the published literature. We report a case of purely cystic pheochromocytoma in a male in 30s who presented to our hospital for unrelated symptom of recurrent burning micturition. He was evaluated for causes of recurrent UTI which revealed incidental right adrenal cyst. The patient's blood pressure was raised on clinical examination and imaging showed simple adrenal cyst without solid component or septations. Suspecting possibility of pheochromocytoma, biochemical analysis was done which revealed elevated 24-hour urinary metanephrine. The diagnosis of cystic pheochromocytoma was made. Adrenalectomy was performed showing cystic lesion in the right adrenal region. Histopathology and immunohistochemistry revealed pheochromocytoma with cystic degeneration. Patient's hypertension resolved during the follow up. In conclusion, purely cystic pheochromocytoma must be considered as differential for adrenal cystic lesions, especially when atypical features are present.