Endoscopic management of a rare granulation polyp in a colonic diverticulum

Abstract

There are many case reports on colon diverticula that cause irritable bowel syndrome, constipation, bleeding, diverticulitis, stricture due to multiple recurrences of diverticulitis, and perforation. However, few articles have examined neoplasms that arise from a diverticulum, such as adenoma and adenocarcinoma, and there have been no reports of granulation polyps that arise from a colon diverticulum after recurrent diverticulitis. We observed a rare granulation polyp that arose from a diverticulum as a result of repeated episodes of local diverticulitis. Narrow band imaging magnified colonoscopy was very useful to diagnose the polyp as a granulation polyp because of the absence of a pit pattern on the surface of the polyp. We successfully resected the polyp using endoscopic mucosal resection. We inverted the diverticulum, and the resected stalk of the polyp was used to close the diverticulum with an over-the-scope clip. If a granulomatous polyp could arise from a diverticulum, differential diagnosis between a colon neoplasm and a granulomatous polyp would not only be difficult but also necessary for suitable endoscopic treatment.

Keywords: Diverticulitis; Endoscopy; Granulation polyp; Mucosal resection; Neoplasm; Recurrence.

Figure 1

Endoscopic mucosal dissection of the sigmoid colon polyp. A: A sigmoid colon polyp approximately 25 mm in diameter; B: Narrow band imaging magnified colonoscopy was performed to investigate the polyp in greater detail. Several irregular microvessels were observed on the surface of the polyp, but there was no pit pattern on the surface; C: A local saline injection was administered, and we observed slight elevation of the polyp; D: After the endoscopic mucosal resection procedure and the removal of the polyp, the diverticulum was identified using the resected stalk of the polyp.

Figure 2

Closure of the diverticulum using the resected stalk of the polyp. A: In a closer view of the resected surface, the cavity of the diverticulum was irregular (the black arrows), and an exposed vessel was identified (red arrow); resection of the polyp indicated that it arose from the diverticulum; B: To prevent bleeding and delayed perforation following the endoscopic mucosal resection (EMR) procedure, we inverted the diverticulum and sutured the inverted diverticulum, including the resected stalk of the polyp, using an over-the-scope clip (red arrows); C, D: After the EMR procedure, computed tomography was performed to examine the soft tissue density around the over-the-scope clip and the increased fat density around the resected site (white arrows).

Figure 3

Histological findings of the resected polyp. A: A 20 magnified narrow band imaging image of the granulomatous polyp; B: A 20 magnified image with a hematoxylin and eosin (HE) stain, the yellow and blue circles in Panel A corresponding to those in Panel B; C: A 100 magnified image with a HE stain reveals significant infiltration of lymphocytes and plasma cells; D: A 200 magnified image with a HE stain reveals increased outgrowth of microvascular structures and infiltration of lymphocytes, neutrophils and plasma cells, which indicates granulation tissue. There were no atypical cells or structural atypia.