Background: Malignancy is one of main distant complications after kidney
transplantation. Except conventional and demographic factors of the risk of
developing renal cell carcinoma-RCC in the native kidney, the time of dialysis, degree of immunological intervention (kind and time of application of immunosuppressive drugs), chronic viral infections and genetic conditionality are also important. Another important factor of the possibility of developing native renal cancer is acquired cystic kidney disease - ACKD.
Material/Methods: In period from June'2007 to August'2008 we hospitalised three kidney recipients of 25, 56 and 45 year old with tumour in their native kidneys. The reason of an end stage renal disease in all patients was glomerulonephritis. Time of dialysis before transplantation was between 1to 5 years. Acute rejection was observed in one patient and it was treated by high doses of steroids. Immunosuppression included calcineurine inhibitors, and steroids.
Results: Period of patient's observation was 18, 14 and 6 months. The abdomen ultrasound was performed every six months and CT and chest X-ray every 12 months. There was no evidence of metastases and neither RCC occurence in the second kidney. The function of two transplanted kidneys after nephrectomy was on the same level as before operation, the third patient has returned on dialysis three months after the nephrectomy. Patients with good graft function had the immunosuppression changed to mTOR inhibitors.
Conclusions: The aetiology of native kidney cancer after renal transplantation is not exactly known. Taking into account the risk of developing renal cell carcinoma and the fact that, the population included in program of transplantation is aging, kidney tumour can become a leading reason for late morbidity and deaths. There is a need for paying extra attention to the problem of monitoring those patients before and after transplantation to determine the risk factors of kidney malignancy, their prevention and treatment.

Keywords: Kidney Transplantation