[LAPAROSCOPIC LYMPHADENECTOMY FOR POSTOPERATIVE LYMPH-NODE METASTASIS OF RENAL MUCINOUS TUBULAR AND SPINDLE CELL CARCINOMA: A CASE REPORT].

We describe renal mucinous tubular and spindle cell carcinoma (MTSCC) that metastasized to the lymph nodes seven years after radical nephrectomy. An 80-year-old man was admitted for treatment of a right renal tumor. A 6.5×6.0-cm tumor in the right kidney (cT1bN0M0) revealed by abdominal computed tomography was treated by laparoscopic radical nephrectomy. The pathological findings at that time suggested papillary renal cell carcinoma type 1. Imaging findings seven years later revealed enlarged pre-caval and right external iliac lymph nodes indicative of delayed metastasis, and these were treated by laparoscopic lymphadenectomy. The pathological findings and re-evaluation of the primary tumor suggested MTSCC. The patient remains free of metastasis at 24 months of follow-up. MTSCC has been a distinct entity in the World Health Organization classification of kidney tumors since 2004. Tumors consist of tubules and cords separated by pale mucinous material in some areas, whereas others have dense cellularity without significant mucin. They are usually of low malignant potential, and metastasis has rarely been reported. To our knowledge, this is the first report of MTSCC with retroperitoneal lymph node metastasis treated by lymphadenectomy.