[Renal neoplasms and renal transplantation: current problems and future perspectives]

Primary carcinomas of the kidney can develop in renal transplantation in four sets of circumstances: (1) detected in the donor, (2) detected as a pre-existing neoplasm in the recipient prior to transplantation, (3) as de novo malignancies arising post-transplantation in the native kidneys of the recipient, (4) or in the graft. In Italy, any renal mass detected during harvesting does not allow the use of any organs for transplantation; however, several reports from other countries have already shown the safety and efficacy of transplanting kidneys with small (<4 cm), unifocal, subcapsular tumors, after resecting the lesion at the back table and verifying the negativity of the surgical margins; this strategy could also be evaluated in Italy to expand the donor pool. Acquired cystic kidney disease (ACKD) is commonly observed in uremic patients undergoing chronic hemodialysis (HD); numerous studies have reported an increased prevalence of renal cell carcinoma (RCC) in association with this nephropathy. The use of ultrasound, computerized axial tomography (CAT) and magnetic resonance imaging (MRI) has greatly improved the ability to detect renal tumors at earlier stages associated with ACKD and the morbidity and mortality rate, in either uremic or transplant patients. RCC in the transplanted kidney is rare and, when recognized, requires nephrectomy. However, a conservative approach with nephron sparing surgery has been reported for selected cases as a useful strategy to treat renal carcinoma in the allograft.