Bladder paraganglioma in adults: MR appearance in four patients

To document the magnetic resonance imaging (MRI) characteristics of paraganglioma of the urinary bladder in adults.

The MRI findings and clinical features of pathologically-proven bladder paraganglioma in four patients (three men, one woman; age range, 39-62 years; mean age, 46.8 years) were reviewed retrospectively. All patients underwent MRI in a 1.5 T instrument. The MRI features of the lesions were analyzed, with emphasis on the size, shape, location, margin, signal intensity, degree of MRI enhancement, and apparent diffusion coefficient (ADC) values.

The bladder paragangliomas were located in the posterior vesicle wall (n=2), in the dome of the bladder wall (n=1), or the inferoanterior wall (n=1). On MR images, the tumors were round (n=1) or oval-shaped (n=3) and all exhibited well-circumscribed margins and broad-based attachment to the bladder wall. On T1-weighted images, the lesions demonstrated homogeneous hyperintensity (n=4) compared to the gluteus maximus muscle; while on T2-weighted images, they showed slight hyperintensity (n=4). On contrast-enhanced MR images, all lesions showed intense enhancement. On diffusion-weighted imaging (DWI), the lesions showed hyperintensity (n=4) and the mean ADC value was 0.973×10(-3) mm2/s.

Bladder pheochromocytoma appears as a round or oval-shaped intensely enhancing lesion with T1 hyperintensity; these characteristics may facilitate the preoperative determination.