Central Journal of Urology and Research Cite this article: Hevia V (2014) Kidneys with Small Renal Tumors: An Acceptable Source for Transplantation. J Urol Res 1(1): 1003. *Corresponding author Hevia V, Department of Urology. Hospital Universitario Ramón y Cajal, Ctra Colmenar km 9, 100, Madrid, Spain, Tel: +34913368760; Email: Submitted: 23 February 2014 Accepted: 28 February 2014 Published: 04 March 2014 Copyright © 2014 Hevia OPEN ACCESS Editorial Kidneys with Small Renal Tumors: An Acceptable Source for Transplantation Vital Hevia, Victoria Gómez, Javier Burgos, Víctor Díez-Nicolás and Sara Álvarez Kidney Transplant Unit, Department of Urology, Hospital Universitario Ramón y Cajal, Spain ABBREVIATIONS KT: Kidney Transplant; ESRD: End-Stage Renal Disease; ECD: Expanded Criteria Donors; RCC: Renal Cell Carcinoma; PN: Partial Nephrectomy; mTOR: Mammalian Target of Rapamycin EDITORIAL Kidney Transplant (KT) is the best treatment for patients with end-stage renal disease (ESRD). Unfortunately, it is not available to every patient with ESRD, and this is mainly due to the increasing number of patients in the waiting list and the shortage of kidneys suitable for transplantation. This fact is a major problem, even in countries with the highest rate of deceased donors in the world, like Spain. Thus, only 58 kidneys Per Million of Population (pmp) are generated, while approximately 100 pmp are needed [1]. Recently, several strategies have been carried out to increase the number of kidneys for transplant, such as Expanded Criteria Donors (ECD), living donors and non-heart-beating donors. Although the pool was increased, it is still insufficient and many patients never have an opportunity to be transplanted, remaining on dialysis and therefore having an important mortality risk, especially in elderly, which is approximately 6.3% per year for patients in the waiting list [2]. Renal Cell Carcinoma (RCC) supposes 3% of all malignancies and its incidence is highest in over 60 years. Most of them are incidental findings and their treatment of choice, when localized, should be Partial Nephrectomy (PN). The increasing age of donors in this era can lead to a higher number of RCC diagnosed, and could reduce theoretically the number of kidneys suitable for transplant. Several studies, with good levels of evidence, suggest that the gold standard treatment for localized RCC should be PN, because it confers the same survival as radical nephrectomy, with a lower risk of severe chronic disease [3]. Local recurrence is estimated around 0% to 4% and the risk of distant metastases is even lower. Moreover, cancer specific survival is around 95% at 5 years. Thus, due to this low risk of recurrence, some Guidelines such as European Association of Urology consider an option to transplant kidneys with small RCC [4]. Only a few groups in literature have reported their experience using these kidneys for transplant, after the tumor excision. First group from Australia presents the largest series in literature [5], with 43 kidneys used for transplantation from patients with renal tumors (38 living donors and 5 deceased). This study has an interesting point of view, due to the approach to kidneys and patients. Patients with renal tumor diagnose had the option of choosing treatment to perform; those who preferred a radical nephrectomy were asked if the kidney could be used for transplantation. After conventional living donor nephrectomy, perfusion and cold storage were performed in conventional fashion, followed by partial nephrectomy and renorraphy. Tumor size was less than 3 cm in all cases, and 31 of them were malignant (25 clear cell, 5 papillary and 1 chromophobe). After a mean follow-up of 32 months, only one patient developed a local recurrence, 9 years after the transplant.No treatment was performed due to refusal of the patient and 18 months later the tumor remained stable. Another group from USA reported 5 living-donor transplants using kidneys with small renal tumors [6], with a size range of 1.0-2.3 cm. Three of them were malignant (RCC Fuhrman Grade 2-3), while the other two were angiomyolipoma. After a median follow-up of 15 months (range 1-41), cancer specific survival was 100% and there was no evidence of local recurrence.Moreover, a Japanese group [7] reported their experience using 42 restored kidneys from living patients, which had benign pathology, aneurysms, ureteral cancers, ureteral strictures… Of the total, 8 had small renal tumors; all of them were pT1a and Fuhrman grade 1 or 2. After 135 months, no tumor recurrence occurred. Most recent article, from a Spanish group, reports 11 transplants with kidneys from 8 donors with tumor. Musquera et al [8] harvested a total of 4 kidneys with small tumors from living donors and 8 from deceased donors with tumor in one kidney(1 of them was not available for analysis because of organ distribution policy). Of the total 11 kidneys, 8 had tumor and the other 3 were the contralaterals. In all cases partial nephrectomy was performed during the bench surgery, assessing histological negative margins before the transplant. Mean age of donors was 47.8 (range 22-72), while mean age of recipients was 53.3 (range 38-73). Tumor size was 14.8 mm (range 3-43 mm), and all cases were pT1a, except one pT1b. Fuhrman grade was low in all cases and all margins were negative.Only one patient developed a surgical complication,