[A case of ureteral malignant lymphoma with concentric thickening of the ureteral wall].

A 59-year-old man was referred to our hospital with right hydronephrosis, which was diagnosed from a medical examination. On imaging studies, he had concentric thickness of the right ureteral wall, and retroperitoneal and mesenteric lymphadenopathy. Urine cytology was negative, and an ureteroscopic biopsy showed no malignancy. We performed laparoscopic biopsy of the retroperitoneal lymphadenopathy, and the histopathological diagnosis was B-cell follicular lymphoma. The patient received four cycles of RCVP (rituximab, cyclophosphamide, vincristine, prednisolone) chemotherapy and four cycles of rituximab monotherapy and then he obtained complete remission. If concentric thickness of the ureteral wall is found, physicians should be aware of the possibility of malignant lymphoma and should consider laparoscopic biopsy for diagnosis.