[A Case of Renal Anastomosing Hemangioma].

A 65-year-old man was found to have a 1.7 cm right renal mass by follow-up abdominal computed tomography for left total nephrectomy after a traffic accident. The renal mass progressed slowly to 2.2 cm in three years and enhanced magnetic resonance imaging revealed marked T2 weighting hyperintensity of the lesion. Although a radiologist (TK) suggested the diagnosis renal anastomosing hemangioma preoperatively, we could not deny the possibility of renal cell carcinoma completely. Therefore, the patient underwent robot-assisted laparoscopic partial nephrectomy. The tumor was successfully removed without any renal arterial clamping or parenchymal excision. Histopathologically, the lesion was composed of capillary-size blood vessels lined by a single layer of endothelial cells, and was diagnosed as a renal anastomosing hemangioma. There were no signs of postoperative recurrence during the 3 month follow-up.