[Malignant lymphoma of the ureter: a case report].

We report a case of malignant lymphoma (ML) of the ureter. A 71-year-old man was admitted to our hospital with the chief complaint of macroscopic hematuria. IVP showed the dilation of left ureter and renal pelvis. Retrograde pyelography showed a 2cm filling defect in the right middle ureter. From the data given, a right ureteral tumor was suspected, and we performed tumor biopsy under an ureteral scope. Since it was diagnosed not as transitional cell carcinoma (TCC) of ureter but as ML with strong inflammation, partial ureterectomy and uretero-uretero anastomosis were done. Histological diagnosis was B cell follicular center lymphoma. Because Ga-scintigraphy revealed no evidence of other involement, it was diagnosed as ML originating from ureter. ML secondarily invading the urinary tract organs is commonly found, but ML originating from the urinary tract is rare. Especially, in regards to ML originating from ureter, only 16 cases have been reported in Japan.