Paraganglioma of the urinary bladder.

Extra-adrenal paragangliomas of the urinary bladder are rare. Typically, patients present with symptoms related to catecholamine hypersecretion or mass effect, but these tumors can also be encountered incidentally on imaging studies obtained for a different purpose. It is important to recognize the key imaging features of this entity so that it may be suggested as a possible differential diagnosis in the setting of a newly identified bladder mass.