Unusual presentation of diffuse large B-cell non-Hodgkin's lymphoma in children: bilateral ureteral involvement.

Non-Hodgkin's lymphomas (NHL) are common malignant tumors in children and adolescents. Among them diffuse large B-cell lymphomas (DLBCL) are relatively rare as compared to non-cleaved small cell lymphoma (mostly Burkitt's-BL) and lymphoblastic lymphoma (LL). While BL has abdominal or cervical site predilection, LL (mostly T-cell) tends to have mediastinal involvement. However, diffuse large B-cell lymphomas may involve abdomen, peripheral lymph nodes, skin, bone, other rare sites. Ureteral NHLs are extremely rare in children; however, many cases have been reported in adults. In adults the histopathology is usually follicular lymphoma. Only one case of unilateral ureter DLBCL has been reported in an adolescent in the past. Here we report a case of bilateral ureteral DLBCL to highlight the unusual presentation of NHLs and that it should be considered in the differential diagnosis of acute renal insufficiency.