Nested variant of urothelial carcinoma: a rare presentation.

We report a rare presentation of a nested variant of urothelial carcinoma with liver and bone metastases in a 74-year-old man admitted to the hospital with bilateral hydronephrosis and acute renal failure. At cystoscopy, both ureters were obstructed, with the right ureter narrowed along its entire length. Subsequent histopathologic examination from the ureteral resection revealed nested variant of urothelial carcinoma. Bilateral stents were placed, and the patient survived 12 months with a good partial response to chemotherapy. A total of 76 cases of nested variant of urothelial carcinoma have been reported worldwide. Our patient was the first, to our knowledge, to present with bilateral hydronephrosis and tumor extension along one ureter.