Polypectomy of a colonic muco-submucosal elongated polyp

A Case of Giant Colonic Muco-submucosal Elongated Polyps Associated with Intussusception

Colonic muco-submucosal elongated polyp (CMSEP), a newly categorized non-neoplastic colorectal polyp, is a pedunculated and elongated polyp composed of normal mucosal and submucosal layers without any proper muscle layer. We herein report a giant variant of CMSEP associated with intussusception in the rectosigmoid colon, with a review of the literature. A 48-year-old woman underwent a laparoscopic low anterior resection due to multiple large submucosal polypoid masses associated with intussusception. Grossly, the colonic masses were multiple pedunculated polyps with a long stalk and branches ranging in size from a few millimeters to 14.0 cm in length. Microscopically, there was no evidence of hyperplasia, atypia, or active inflammation in the mucosa. The submucosal layers were composed of edematous and fibrotic stroma with fat tissue, dilated vessels, and lymphoid follicles.

Colonic mucosubmucosal elongated polyp: report of a series of 14 cases and review of the literature

AIMS

Most colorectal polyps can be reliably assigned to one of the known polyp categories, but a subset of polyps named colonic mucosubmucosal elongated polyps (CMSEPs) do not fall into any of these categories. First described in the Japanese literature, CMSEPs seem to be under-recognized in the Western literature. The aims of this study were to describe the clinicopathological features of 14 CMSEPs, discuss potential pathogenetic mechanisms, and increase awareness of this entity among pathologists.

METHODS AND RESULTS

Fourteen pedunculated colorectal polyps that met the histopathological criteria for CMSEP (as described by Matake et al. and Alizart et al.) were assessed (12 males and two females; mean age 59.7 years). Five polyps were located in the sigmoid colon, four in the rectum, two in the descending colon, and three in the colon not otherwise specified. Nine of 14 polyps were discovered incidentally: two of nine on routine screening colonoscopy, two of nine on surveillance colonoscopy for inflammatory bowel disease (IBD), and five of nine upon surgical intervention for carcinoma or IBD. None coexisted with diverticular disease. The polyps were long and slender, varied from 5 to 30 mm in length (mean 15.9 mm), and showed a normal-looking colonic mucosal layer and underlying loose submucosa with thick-walled and congested blood vessels and lymphatics.

CONCLUSIONS

CMSEPs show subtle but distinctive pathological features, and occur in normal and diseased colons. Pathologists need to be aware of this entity, to avoid confusion with other more commonly encountered colorectal polyps. With increasing colon cancer screening programmes and surveillance colonoscopy, it is likely that CMSEPs will be encountered more often.

Familial Occurrence of Enteric Muco-Submucosal Elongated Polyp

We report 2 cases of enteric muco-submucosal elongated polyps (EMSEPs) that presented with gastrointestinal bleeding. The 2 patients are siblings. They both had a history of percutaneous coronary intervention for coronary artery disease and were on dual antiplatelet therapy. They underwent endoscopic resection of the polyps, which displayed identical endoscopic and histological features compatible with EMSEP. This is the first report of familial occurrence of EMSEP, suggesting possible genetic involvement. It is also important to note that the use of antiplatelet agents appears to be a predisposing factor for gastrointestinal bleeding from EMSEP.

Muco-submucosal elongated polyps of the gastrointestinal tract: A case series and a review of the literature

We present three cases of gastrointestinal muco-submucosal elongated polyps, two located in the duodenum and one in the descending colon. All three cases had a characteristic, “worm-like” endoscopic appearance and were lined by unremarkable mucosa. The vascular component was located in the submucosa and was composed of a mixture of variably dilated blood vessels (capillaries and veins) and lymphatics. The duodenal polyps displayed lipomatous metaplasia of the submucosal stroma. The dual vascular phenotype of the vascular component was confirmed by immunohistochemistry with D2-40 and CD31.