BK Virus–Associated Urothelial Carcinoma of a Ureter Graft in a Renal Transplant Recipient: A Case Report

BackgroundUrothelial carcinomas of ureter grafts in renal transplant patients are rare. Here we report our experience with a case of BK virus–associated urothelial carcinoma in a ureter graft.Case ReportA 47-year-old man developed chronic renal failure secondary to diabetes mellitus and started maintenance hemodialysis in September 2007. Two months later, the patient received a renal transplant from his 70-year-old mother. The patient developed BK virus–associated nephropathy 1 year after transplantation and presented with a decline in renal function and hydronephrosis in the transplanted kidney 4 years 6 months after transplantation. Cystoscopy and retrograde pyelography revealed an irregular filling defect in the ureter graft. Cytologic diagnosis of his urine revealed a high-grade urothelial carcinoma. Computerized tomography showed a cT2 ureteral tumor and no involvement of other organs. The patient subsequently underwent a transplant nephroureterectomy with bladder cuff resection. Histopathologic findings revealed a high-grade urothelial carcinoma, pT2, in the ureter graft with SV40-positive staining. The patient was closely observed without adjuvant chemotherapy therapy and remained disease free 1 year after surgery. Renal transplant recipients with BK virus infection are at high risk of developing urologic malignancies. Close attention is necessary to diagnose post-transplantation urologica malignancies as early as possible.