Early-Onset Bilateral Clear Cell Renal Cell Carcinoma in a Pediatric Renal Transplant Recipient: A Rare Case Report.

Background: Renal transplantation (RTx) is the preferred treatment for end-stage renal disease (ESRD), reducing mortality and improving quality of life. However, long-term immunosuppression increases the risk of malignancy, with renal cell carcinoma (RCC) occurring in approximately 0.6%-0.7% of renal transplant recipients, most commonly arising in the native kidneys. Bilateral RCC is rare and is typically associated with papillary histology and acquired cystic kidney disease (ACKD). Case Presentation: A 16-year-old male with ESRD secondary to diffuse mesangial hypercellularity underwent living-related renal transplantation from his mother. Fourteen months posttransplant, routine ultrasonography revealed bilateral renal masses in the native kidneys. Contrast-enhanced computed tomography confirmed multiple lesions in both kidneys. The patient underwent bilateral laparoscopic nephrectomy. Histopathology revealed bilateral clear cell renal cell carcinoma, confined to the kidneys with negative surgical margins. Multiple benign cortical cysts suggested early acquired cystic kidney disease. At 1-year follow-up, the patient showed no evidence of recurrence, with normal serum creatinine and stable graft function. Discussion: Bilateral RCC after renal transplantation is rare and is usually associated with papillary histology and acquired cystic kidney disease. The early occurrence of bilateral clear cell RCC in a pediatric transplant recipient is unusual and may indicate an underlying predisposition. Early detection through routine imaging allowed timely surgical management with preservation of graft function. Conclusion: This case highlights the rare occurrence of early bilateral clear cell RCC in a pediatric renal transplant recipient. Careful surveillance of native kidneys in transplant recipients may facilitate early diagnosis and favorable outcomes.