A rare case of primary retroperitoneal transitional cell carcinoma achieving pathological complete response with combined modality treatment.

Abstract: Primary retroperitoneal transitional cell carcinomas (TCCs) are very rare tumors arising from the urogenital ridge remnants. Till date only eight cases have been reported. Recently, we treated a patient who presented with an advanced, large tumor with major vascular infiltration with chemotherapy and radiotherapy before surgery. Though preoperative imaging did not show much response, the tumor could be resected completely along with the left kidney and part of the abdominal wall. Final histopathological examination revealed no viable tumor in the entire specimen. This case report details the clinical and management aspects of such a rare tumor with a review of the previously reported cases.