Urothelial Carcinoma Arising on a Functional Kidney Graft

<b>Introduction</b>: Kidney transplant recipients present a higher risk of developing malignancies than the general population. Malignancies represent the third leading cause of death for kidney transplant recipients. There is an increased risk of developing urothelial carcinoma among kidney transplant recipients, but it is not as high as the risk of renal cell carcinoma, which is the most common urologic malignancy. Although the bladder is the most common location for urothelial carcinoma, urothelial carcinomas of the upper tracts of the native kidneys and the allograft are also reported. The estimated incidence of urothelial carcinomas arising on kidney grafts is 0.019%. <b>Case report:</b> We present a case of a kidney transplant recipient who developed non-muscle-invasive bladder cancer 10 years after the transplant. This was successfully treated with TURBT (transurethral resection of the bladder tumor) and BCG (bacillus Calmette-Guerin) instillations. Two years later, this patient developed metastatic urothelial carcinoma of the allograft. <b>Discussion:</b> Nephroureterectomy of the transplant with bladder preservation after BCG treatment, no systemic chemotherapy, and cessation of immunotherapy were the treatments of choice in this case. Local oncologic control and spontaneous complete regression of pulmonary metastasis were obtained at a 2-year follow-up. <b>Conclusions:</b> With this case, we emphasize the fact that managing urothelial carcinomas in kidney transplant recipients is a provocative challenge for surgeons, nephrologists, and oncologists, as there are no treatment guidelines or protocols.