Port site metastasis of sigmoid colon cancer after a laparoscopic sigmoidectomy: report of a case.

A 75-year-old woman with TNM stage I (T2, N0, M0) sigmoid colon adenocarcinoma underwent a laparoscopy-assisted sigmoidectomy. Five months later, the patient developed two subcutaneous metastases at two trocar sites. A second operation was performed and two abdominal wall masses were resected, but the operation revealed no evidence of peritoneal dissemination, liver metastasis, or lymph node metastasis. The histological findings confirmed the diagnosis of metastatic carcinoma of the sigmoid colon. Large-scale studies have shown the actual rate of port site metastasis to be similar to that observed in open surgery, and therefore the rate is much lower than that initially reported in small studies. However, the metastatic mechanism has not yet been clarified. These results suggest that port site metastasis can be prevented as effectively as during open surgery by utilizing accurate operating skills based on the sound principles of tumor surgery. Therefore, it is very important that appropriate operating procedures and an effective training system are established.