Two patients with bladder pheochromocytoma are presented and 22 previously published cases are reviewed. From the analysis of these 24 patients the following conclusions are made: bladder pheochromocytoma may appear at any age but is more common in the second and fourth decades. Females are more often affected than males. The clinical diagnosis is established when a combination of nonspecific urinary symptoms and those related to the secretion of catecholamines occur. However, the most accurate method for the preoperative diagnosis of bladder pheochromocytoma is the determination of catecholamines or their metabolites in the urine or the blood. The biologic behavior, pathologic features, histochemical reactions, and ultrastructural characteristics of bladder pheochromocytoma are similar to those of pheochromocytomas from other sites.
HEOCHROMOCYTOMAS USUALLY ARISE I N THE P adrenal medulla, however, it has been welldocumented that approximately 10% of pheochromocytomas in adults and 31% i n children may develop i n extraadrenal chromaffin tissues.28 Thus, primary pheochromocytomas have been described in the neck,7 mediastinum,8 retroperitoneum,ll and urinary bladder.10
Most bladder pheochromocytomas give rise to special clinical features that, when properly evaluated, allow their recognition. However, as with pheochromocytomas of other sites, the preoperative diagnosis of bladder pheochromocytoma can be made with certainty by biochemical means.0, 20 This is of practical importance since complete excision of the tumor is usually followed by relief or disappearance of all signs and symptoms, including hypertension, but operative procedures on patients with undiagnosed pheochromocytomas are associated with a high mortality rate.20
T h e purpose of this paper is to report 2 cases of pheochromocytoma of the bladder observed at the General Hospital of Mexico City during a 14-year period and to review 22 previously published cases. In addition,