[Endoscopic Submucosal Dissection(ESD)as a "Loco-Regional Cancer Therapy" for Colorectal Tumors].

INTRODUCTION: Endoscopic submucosal dissection(ESD)for colorectal tumors has been covered by the national health insurance system in Japan since April 2012, and is widely used. We analyzed colorectal ESD cases we performed. PATIENTS AND METHODS: We investigated 515 patients with colorectal lesions(580 lesions)for whom ESD was performed between November 2005 and April 2017. Clinicopathological data, technical methods, complications, and outcomes were analyzed. RESULTS: Most tumors were found in the transverse colon(134 lesions). The average diameter was about 26 mm. The largest lesion was 120 mm. The en bloc resection rate was high(96.2%). The average operative time was 51 minutes. Among complications, the number of delayed major bleeding cases was 7(1.2%). Minor perforations occurred in 3 cases(0.5%). The perforation could be closed with endoscopic clips. About 70% of the cases were adenomas, and the remainder were carcinomas. One patient with carcinoma in situ showed a mucosal recurrence 4 months later and received repeat endoscopic treatment. The cure rate was 99.8%. Among 29 deep submucosal invasion cases, additional colectomy was performed in 21; 3 patients had persistent carcinoma in the colonic wall and another patient had lymph node metastasis. CONCLUSIONS: Colorectal ESD can be performed for all sites in the large intestine, and en bloc resection was possible for a large lesion. A good outcome was observed for "Loco-Regional Cancer Therapy" in early colorectal carcinoma.

A Case of Benign Schwannoma of the Transverse Colon with Granulation Tissue.

Schwannomas occurring in the gastrointestinal tract are rare, and among them, schwannomas of the large intestine are extremely rare. In this paper, we report a case of a macroscopically atypical schwannoma of the transverse colon. The case is a female aged 67. Stool occult blood test was positive, and colonoscopy revealed a protruded lesion resembling a type 1 carcinoma measuring 4 cm with a reddish and uneven surface on the transverse colon. The surface was smooth and lobulated in observation with indigo carmine spray, and granulation tissue was revealed by biopsies. CT of the abdomen showed an irregular mass, and clinical examinations could not rule out malignancy. Therefore, partial transverse colectomy with peripheral lymph node dissection was performed. Histologically, proliferation of spindle cells was observed originating from the muscularis propria, and most of the upper part of the lesion was replaced by granulation tissue. In immunohistochemical staining, S-100 protein and NSE were positive while KIT, CD34, desmin and smooth muscle actin were negative, and the tumor was therefore diagnosed to be a schwannoma. In addition, since the MIB-1 labeling index was low and virtually no mitosis was observed, it was diagnosed as benign tumor.