Intra-abdominal desmoid tumor mimicking local recurrence of renal cell carcinoma after laparoscopic partial nephrectomy

A 64-year-old man had an intra-abdominal mass that was detected in a follow-up examination after laparoscopic partial nephrectomy for renal cell carcinoma (RCC). CT showed an enhanced mass of 2.5-cm diameter near the right kidney, where partial nephrectomy had been performed. Local recurrence of RCC with duodenum invasion was suspected, and excision was performed. The final pathological diagnosis of desmoid tumor differed from the preoperative diagnosis. Therefore, we report this case as a rare example of intra-abdominal desmoid tumor mimicking local recurrence of RCC. To our knowledge, this is the first report of intra-abdominal desmoid tumor after laparoscopic partial nephrectomy.