Localized amyloidosis of the genitourinary tract: report of 5 new cases and review of the literature.

Primary localized amyloidosis of the genitourinary tract is a rare entity characterized by small pseudotumors localized in the renal pelvis, ureters, or bladder. Amyloid fibrils are derived from immunoglobulin light chains, but no systemic plasma cell proliferation is detected. The clinical and radiologic features mimic urinary tract cancer, and local treatment is indicated. The prognosis is excellent in most cases, although disease recurrence is possible. We report 5 new cases of localized amyloidosis of the urinary tract, with lambda (4/5), or kappa (1/5) chain amyloid protein, involving the bladder (5/5), and the ureter and renal pelvis (1/5), with multiple, bilateral lesions in 1 case. The presenting complaint was painless hematuria in 4 cases. All cases were of primary (AL)-type amyloidosis. All patients underwent extensive investigation, and none presented any signs of generalized amyloidosis. A favorable outcome was observed in every case. We performed a comprehensive review of the literature, and summarize the data.