[A Case of Resection of Para-Aortic Lymph Node Recurrence and Peritoneal Recurrence Following Sigmoid Colon Cancer Surgery].

In June 2010, a 73-year old man diagnosed with sigmoid colon cancer underwent laparoscopic sigmoidectomy. The histopathological diagnosis was tub2, pSS, n (-), stageⅡ.Vascular invasion was present; however, at the patient's request, no adjuvant chemotherapy was administered.Computed tomography (CT) performed at the outpatient follow-up 4 years and 6 months after the surgery revealed a para-aortic lymph node metastasis in the caudal aspect of the left renal artery branch point. No other definite mass shadows were detected. Positron emission (PET)-CT revealed high tracer accumulation (SUVmax) not only in the CT-identified lymph node, but also near the site of the anastomosis in the bowel. Considering that no tracer accumulation was detected at any other sites and the patient's compliance with medication and scheduled visits was poor, surgical resection rather than chemotherapy was adopted as the treatment strategy. No metastases other than at the sites identified by the diagnostic imaging were found during the surgery. Since the findings on palpation did not rule out the possibility that the nodule near the anastomotic site was present inside the intestinal tract, lymph node dissection, resection of the intestinal tract including the anastomotic site, and re-anastomosis were performed. The most likely diagnosis based on the histopathological findings was dissemination for both the adenocarcinoma and the nodule near the anastomotic site. At present, the patient is being treated with adjuvant chemotherapy. In the Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines for the Treatment of Colorectal Cancer, the recommended therapeutic intervention is surgical resection of hematogenous metastases; however, no treatment is specified for lymph node metastases. In general, chemotherapy is administered for distant metastases. However, we have found no reports of cases in which a complete remission has been achieved. There are reports of improvement of survival by surgical resection in cases with solitary lymph node metastasis or isolated dissemination of colorectal cancer. These observations suggest that surgical therapy may have contributed to the improved prognosis in the present case.