Ultrasound-guided percutaneous ablation of a renal mass in a renal allograft.

A 50-year-old man underwent magnetic resonance imaging and was found to have an incidental 3.2-cm mass in a renal allograft. Because of the multiple comorbidities associated with renal allograft patients, a minimally invasive option such as percutaneous ablation should be considered. The patient underwent percutaneous ultrasound-guided cryoablation. The final histopathologic examination of the needle biopsy was consistent with an oncocytic neoplasm. The 9-month follow-up contrast-enhanced magnetic resonance imaging scan showed no residual tumor. Long-term follow-up and greater clinical experience are still necessary to confirm the efficacy of cryoablation for allograft lesions.