[A Case of Laparoscopically Assisted Local Resection of Early-Stage Sigmoid Colon Cancer Arising within a Diverticulum].

The patient was a 79-year-old male in whom a neoplastic lesion was found in the sigmoid colon diverticulum during a follow-up colonoscopy for colorectal adenoma. Endoscopic treatment was difficult, and the patient was referred to our department for surgery. The patient had many underlying diseases, including angina pectoris, interstitial pneumonia, and diabetic nephropathy, and the decision was made to perform local resection as a minimally invasive treatment. The patient was treated with laparoscopic excision of the sigmoid colon, followed by a small laparotomy and intraoperative endoscopy to open the colon for local resection. Pathology results showed a 5 mm pTis with R0 resection. Early-stage cancer of the diverticulum is often difficult to treat endoscopically due to the limited space available for manipulation. Local excision, as a minimally invasive treatment, is also a useful option when several underlying diseases are present, as in this patient.