A 66-year-old white man underwent a cadaveric renal transplant for end-stage renal disease (ESRD) secondary to hypertension in 1993. During the routine follow-up, the serum creatinine had risen from a baseline of 29 to 40 mg/L. The patient underwent renal ultrasonography (Fig. 1), which showed a 1.5-cm lesion and this was biopsied. The pathological diagnosis of the mass was clear cell carcinoma. During further evaluation MRI showed a 3.0-cm mass in the right native kidney. The patient underwent a right radical nephrectomy, the pathology being consistent with a papillary carcinoma. Because the lesion was small and peripheral in the allograft it was treated using percutaneous cryoablation with the CryohitTM system (Galil Ltd., Tel Aviv, Israel) (Fig. 2). The treatment was monitored with MRI, as described previously . A 3-mm cryoprobe was used to create a freeze ‘front’ extending 5-mm beyond the border of the lesion, with a probe tip temperature of −140°C. There were no complications and the patient's creatinine level remained stable. At the 1-month follow-up the cryoablated lesion measured 1.5 cm, with no enhancement on MRI.
The development of RCC in a transplanted kidney is rare, with a recent report finding only 24 cases in the allograft kidney, from 7596 cases reviewed . The usual treatment of these tumours required either an allograft nephrectomy or partial nephrectomy . Recent developments have led to the use of minimally invasive therapies such as percutaneous cryoablation for treating small renal cancers. Standard treatment for RCC consists of either a partial or radical nephrectomy, depending on the size of the tumour. Recent advances in imaging have allowed the development of minimally invasive image-guided therapy. We reported our initial series of 20 patients who underwent percutaneous cryoablation under MRI guidance, with minimal morbidity . As indicated here, a small tumour in a transplanted kidney represents an ideal case for minimally invasive therapy. The ability to avoid open surgery in an immuno-compromised patient is a distinct advantage for percutaneous cryoablation. While continued follow-up will be necessary to assure adequate treatment, in future percutaneous cryoablation may be the preferred method of treating small renal tumours in immuno-compromised patients.
W.B. Shingleton, MD, Associate Professor of Surgery.
P.E. Sewell, MD, Associate Professor of Radiology.
W.B. Shingleton, University of Mississippi Medical Center, Division of Urology, 2500 North State Street, Jackson, Mississippi 39216, USA. e-mail: email@example.com