[A case of needle tract implantation of ureteral carcinoma].

Malignant metastasis along the needle tract, called "needle tract implantation" (NTI), has been demonstrated for numerous carcinomas, including prostate, colon and liver. We report a case of NTI of ureteral carcinoma following percutaneous nephrostomy tube replacement. A 57-year-old woman was found to have a subcutaneous mass at the site of nephrostomy. She had a past history of right nephroureterectomy for ureteral carcinoma about one year earlier, and a nephrostomy tube had been inserted before diagnosis postoperatively. We resected the subcutaneous mass. Pathological diagnosis was urothelial carcinoma closely resembling right ureteral carcinoma. To our knowledge, this is the seventh reported case of NTI of upper urinary tract urothelial carcinoma. Percutaneous manipulation carries a potential risk of local tumor spillage and NTI in the nephrostomy tract.