Living-donor transplantation after excision of unrecognized renal cancer diagnosed after transplant.

Background: Published data on kidneys transplanted after resecting small renal cancers during the transplantation surgery are very rare and, to the best of our knowledge, no pediatric cases have been reported in the literature.

Case-diagnosis/treatment: Our patient was diagnosed with a bilateral Wilms tumor when he was 15 months old. A total bilateral nephrectomy was required to control the disease. Two years later, a human leukocyte antigen (HLA)-identical living-donor transplant from his father was performed. A small mass in the father's left kidney was diagnosed as an angiomyolipoma during the pretransplant donor evaluation. During the surgery, the mass was excised and the kidney implanted. One week later, the pathological study revealed the mass to be a clear cell renal carcinoma. After joint discussion, the urologic and nephrologic teams and the family decided to maintain the transplant, managing the patient with monotherapy based on rapamycin and close ultrasound control. To date, 8 years after transplantation, no signs of malignancy have been detected, and renal function is normal.

Conclusion: This is the first reported pediatric case of a living-donor graft with a small renal carcinoma excised in the operating room. No malignancy has been observed in 8 years of follow-up.