[A Case of Sigmoid Colon Cancer Recurrence at the Hand-Sewn Anastomosis Site Originated from Tumor Implantation].

We report a case of anastomotic recurrence following laparoscopic sigmoidectomy with hand-sewn anastomosis, which was attributable to the implantation of exfoliated cancer cells. A 78-year-old man diagnosed with early colon cancer underwent endoscopic submucosal dissection(ESD); however, ESD was suspended due to infiltrated muscle fibers. Subsequently, he underwent laparoscopic sigmoidectomy with hand-sewn anastomosis, accompanied by D3 lymph node dissection. Histopathological findings revealed a well-differentiated tubular adenocarcinoma, pT2(MP), tub1>tub2>por2, ly0, v1, PM0, DM0, RM0, N0M0, pStage Ⅰ. The follow-up CT 6 months after surgery, showed enhanced wall thickening and irregular surface of the sigmoid colon. Colonoscopy revealed a type 2 tumor located on the anastomotic line. Based on the diagnosis of anastomotic recurrence, the patient underwent partial colectomy. Histopathological findings were similar to those of the primary tumor and suggested implantation of exfoliated cancer cells as the origin of anastomotic recurrence. Cancer cells had infiltrated all layers. In conclusion, we recommend the performance of appropriate operative procedures to prevent anastomotic recurrence, such as the cleaning of the anastomosed intestinal tract. Careful follow-up in colon cancer patients is of the utmost importance and the risk of anastomotic recurrence should always be considered.