Early colon cancer within a diverticulum treated by magnifying chromoendoscopy and laparoscopy

Abstract

We report a unique case of intramucosal carcinoma in a tubulovillous adenoma arising from a single diverticulum. Endoscopic mucosal resection (EMR) was carried out successfully and completely with the assistance of laparoscopy. A 71-year-old man was admitted to our hospital because of melena and anemia. Emergent colonoscopy showed diverticulosis in the right-sided colon. However, endoscopy could not exactly detect the bleeding site. A flat elevated polyp was found within a single diverticulum located in the descending colon and diagnosed as an intramucosal carcinoma, as magnifying chromoendoscopy revealed a type IV pit pattern. As his diverticular bleeding repeated, a right-sided hemicolectomy was decided for treatment, the polyp within the diverticulum was also completely removed by EMR with the assistance of laparoscopy. Although a colonic perforation was detected immediately after EMR, the perforation was closed with endoclips intraluminally and also repaired laparoscopically from the serosal side. Histologically, the resected lesion was an intramucosal well-differentiated adenocarcinoma and the surgical margin was free of tumor.

Figure 1

Colonoscopy and magnifying chromoendoscopy. A: Colonoscopy showing a single diverticulum in the descending colon and a flat elevated polyp (15 mm in diameter) within the diverticulum; B: Magnifying chromoendoscopy using 0.4% indigo-carmine dye spraying revealing a type IV pit pattern according to Kudo’s classification; C: Endoscopy showing a pin-hole perforation immediately after endoscopic mucosal resection (EMR); D: Magnifying chromoendoscopy displaying negative neoplastic changes in the removed lesion.