Non-Hodgkin's lymphoma of the bladder--CT and MRI appearances.

Computed tomography (CT) appearances of two patients with primary bladder non-Hodgkin's lymphoma are presented with magnetic resonance imaging (MRI) correlation in one. The differences between primary and secondary bladder lymphoma with respect to their clinical presentation, course and prognosis are described. Bladder lymphoma is a rare tumour which often presents as a large multilobular submucosal mass, and such an appearance may suggest the diagnosis. Bladder lymphoma, however, cannot be differentiated from the more common transitional cell carcinoma on the basis of CT attenuation values or enhancement patterns, or MRI signal characteristics. The diagnosis must, therefore, be made by histology. Other differential diagnoses and the role of various imaging techniques in the diagnosis and management of bladder lymphoma are considered.