Chronic lymphocytic leukemia/small lymphocytic lymphoma presenting as acute renal failure.

Lymphoma of the urinary bladder is quite rare, accounting for a small percentage of all bladder neoplasms. Here we discuss the case of a 68-year-old male patient who initially presented with acute renal failure and severe bilateral hydronephrosis on ultrasound. Cross-sectional imaging further revealed a diffusely thickened bladder wall with extensive retroperitoneal and mesenteric lymphadenopathy. Bladder biopsies ultimately led to a diagnosis of stage IV chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). This is a rare instance of upper tract dilatation being the first sign of a widely disseminated hematologic malignancy.