A Rare Case of Donor-Derived Renal Cell Carcinoma in a Kidney Transplant Recipient.

BACKGROUND The incidence of renal cell carcinoma (RCC) in transplanted kidneys is reported to be about 0.2%, which makes this case exceedingly rare. Risk factors include older age of the donors, smoking, obesity, and hypertension. Higher incidences of allograft RCC have been seen in patients who received a kidney from a deceased donor rather than from a living donor. CASE REPORT A 71-year-old woman with end-stage renal disease underwent deceased donor kidney transplantation (DDKT) 1 year before presentation. The immune-suppressive regimen was Envarsus, Myfortic, and prednisone. Allograft functioned with a baseline creatinine of 1.4-1.5 mg/dL. The patient presented due to recurring UTIs, which prompted the ultrasound that showed a mass on the allograft. Abdominal MRI demonstrated a 3.5-cm mass in the upper pole. Biopsy showed clear-cell RCC, Fuhrman nuclear grade 3. The patient underwent a partial nephrectomy. Following the nephrectomy, baseline serum creatinine was 1.7-2 mg/dL. The patient was discharged with immunosuppressive therapy consisting of Myfortic, prednisone, and Rapamune after diagnosis. CONCLUSIONS There are no standard treatment guidelines or optimal immune therapy for the management of allograft RCC in renal transplant recipients. Options include radical nephrectomy, nephron-sparing surgery (NSS), radiofrequency ablation (RFA), and active surveillance. According to a systematic review, the recurrence of cancer after partial nephrectomy was 3.6% after 3.1 years, which was similar to non-transplanted kidneys. There is not enough evidence to support screening for RCC in patients with transplanted kidneys, but constitutional symptoms like recurrent UTIs should prompt further investigation for potential malignancies in these patients.