A Case of Difficult Diagnosis of an Ectopic Giant Pheochromocytoma in a Patient Who Presented with Abdominal Pain

Abstract

A 62-year-old woman was admitted to our hospital complaining of abdominal pain of sudden onset, and enhanced abdominal computed tomography（CT）showed an 8.5-cm-sized tumor on the posterior surface of the left lobe of the liver, without unequivocal extravasation. Three days later, emergency surgery was performed because of progression of anemia and growth of the tumor. Intraoperatively, a mass was observed under the lesser omentum, which was resected to the extent possible. The histopathological findings were consistent with a pheochromocytoma. The patient showed no typical symptoms such as high fever, hypertension, or hyperhidrosis, either prior to or during the surgery, making the diagnosis difficult. The postoperative course of the patient was satisfactory and the tumor showed no apparent recurrence. Ectopic occurrence of pheochromocytoma accounts for about 10％ of all cases, and is common around the abdominal aorta. The diagnosis of giant and ectopic pheochromocytomas is often difficult because of the lack of typical symptoms. In this article, we report a case of ectopic giant pheochromocytoma that was difficult to diagnose preoperatively.