A case of extra-adrenal pheochromocytoma diagnosed by intraoperative abnormal hypertension

Abstract

A 57-year-old woman was referred to our hospital with a suspicion of hepatocellular carcinoma. An abdominal CT scan revealed a 30 mm-sized hypervascular tumor beside the liver caudate lobe. Further examinations could not determine whether this was a hepatic tumor or a neurogenic tumor. A urinary analysis showed no elevations of catecholamines. During laparotomy, incision of the lesser omentum disclosed a hypervascular tumor outside the liver on the inferior vena cava. Palpation of the tumor caused a sudden increase in the systolic blood pressure to 250-300 mmHg. We diagnosed the tumor as an extra-adrenal pheochromocytoma. We performed tumorectomy after administration of a hypotensive drug (i.v. nicardipine). The postoperative course was uneventful. She has had no signs of recurrence for 18 months after the operation. Preoperative diagnosis could not be made in this case, because it was difficult to differentiate from a hepatic tumor and the urinary analysis showed no abnormal levels of catecholamines. When we encounter a para-aortic neoplasm of unknown origin, extra-adrenal pheochromocytoma should be kept in mind as a possible differential diagnosis.