Adrenal hemorrhagic pseudocyst as the differential diagnosis of pheochromocytoma — A review of the clinical features in cases with radiographically diagnosed pheochromocytoma

Background: Clinical diagnosis of pheochromocytoma is difficult for some adrenal tumors. Aim: Herein, we review clinical and pathological findings of 31 cases with radiographically diagnosed pheochromocytoma, including three cases of hemorrhagic pseudocysts (HPC). Materials/subjects and methods: Between January 1992 and December 2010, 31 patients with adrenal tumors were pre-operatively diagnosed as having pheochromocytoma by radiographic imaging, and underwent adrenalectomy. Histological examination revealed HPC in 3 patients (9.7%), and pheochromocytoma in the remaining 28 patients. We reviewed and compared the clinical features, including the biochemical and radiographic features, of HPC and pheochromocytoma cases. Results: Biochemical testing showed no definitive excessive catecholamine secretion in any of the three patients with HPC and four (14.3%) of those with histologically proven pheochromocytoma. 131I-metaiodobenzylguanidine scintigraphy was negative in the three with HPC, but positive in all of the four with pheochromocytoma who did not have suggestive biochemical results. All HPC patients had concomitant disease or symptoms suggestive of pheochromocytoma, and two had received an anti-coaglant or anti-platelet agent. Laparoscopic surgery was completed in two cases of HPC uneventfully. Conclusions: Adrenal HPC may have radiographic characteristics similar to those of pheochromocytoma. Adrenal HPC should be considered as a differential diagnosis of pheochromocytoma.