Noninvasive Therapy of Incidental De Novo Renal Cell Carcinoma in a Kidney Allograft 12 Years After Transplantation: Report of a Case and Review of Literature

Background: Immunosuppressive therapy increases the incidence of posttransplantation cancer. Primary renal cell carcinoma (RCC) represents 4.6% of all cancers in transplant recipients. The treatment options for RCC in a renal allograft include radical nephrectomy or nephron-sparing surgery. We report the case of a patient who underwent percutaneous radiofrequency ablation (RFA) of a RCC in the grafted kidney. Patient and Methods: Twelve years after undergoing heterotopic, allogenic kidney transplantation, a de novo lesion was diagnosed in the upper pole of the kidney graft in a 77-year-old patient during routine duplex ultrasonography. The magnetic resonance image showed a spherical lesion of 17 mm in diameter, which undoubtedly showed radiological signs of a RCC. After adequately informing the patient about alternative treatment strategies and the associated risks, we made an interdisciplinary decision for a percutaneous RFA of the lesion. Results: After the intervention, graft function remained unchanged and is still good at 6 months with no signs of local recurrence on follow-up MRI. A small coagulation defect at the site of the former lesion was the only morphological change. There was also no evidence of distant tumor spread. Conclusion: Percutaneous RFA seems an acceptable, allograft-preserving treatment option associated with low morbidity and mortality for RCC in a renal allograft considering the significant risks associated with open partial nephrectomy in a kidney graft.