MIBG Localization of a Subclinical Paraganglioma of the Bladder.

Urinary bladder paragangliomas are very rare, and the majority are hormonally active. Nonfunctioning paragangliomas are even rarer and more difficult to diagnose because of absence of catecholamine secretion. We present a 27-year-old woman with an asymptomatic paraganglioma of the urinary bladder discovered incidentally in a patient with prior resection of a functional pararenal paraganglioma. Metabolic profiles and cystoscopy were nondiagnostic. We demonstrate the increased sensitivity of I-MIBG SPECT/CT compared with planar scintigraphy for detection of a nonfunctional paraganglioma of the urinary bladder, which makes it valuable in evaluation of functional and nonfunctional paragangliomas.