Pheochromocytoma of the Urinary Bladder

Abstract

Paraganglioma of the urinary bladder is rarely encountered. It accounts for less than 0.5% of bladder tumors 1 and only 1% of all pheochromocytomas. Pheochromocytomas that arise outside the adrenal gland are termed extra-adrenal pheochromocytomas or paragangliomas. The most common signs and symptoms are hypertension and hematuria. 2 If the presence of pheochromocytoma is suspected on clinical grounds, imaging studies are useful in localizing the tumor. 3 Computed tomography (CT) is frequently used because of its high sensitivity for detecting adrenal (94%) and extra-adrenal (82%) pheochromocytomas. Magnetic resonance imaging (MRI) is more sensitive than CT for detecting small extra-adrenal pheochromocytomas because of its inherent tissue contrast resolution.3 The [ 1 3 1 I]metaiodobenzylguanidine (MIBG) scan is regarded to be highly specific for bladder pheochromocytoma; however, its use is limited because of its expense and restricted availability. 4 In this report, we have described the clinical, laboratory, imaging, radionuclide, and histopathologic features of this uncommon tumor. Thus, in patients with similar unusual symptoms and increase in blood pressure with micturition, a clinical diagnosis of pheochromocytoma of the urinary bladder must be considered. Imaging studies such as ultrasonography (USG), CT, MRI, and [ 1 3 1 I]MIBG scans will help in confirming the diagnosis and localizing the tumor. Pheochromocytoma of the urinary bladder is a rare tumor with striking and unusual manifestations.