A stalk with no polyp-A muco-submucosal elongated polyp in the duodenum.

A 62-year-old Caucasian man was referred for upper GI endoscopy with a 6-month history of intermittent abdominal pain, nausea and bloating. Endoscopy revealed a 5-cm elongated lesion arising in D2. A pedunculated polyp (0-Ip) was suspected; however, deeper intubation revealed no polyp at the end of the stalk (Figure 1). Narrow band imaging did not reveal any adenomatous or suspicious features (Figure 2). The base of the polyp was injected with EMR solution (gelofusin, methylene blue and adrenaline 1:100,000), resected by snare cautery (Figure 3) and the defect was closed with two endoclips. Histopathology confirmed a 42 mm × 15 mm cylindrical lesion of hyperplastic duodenal mucosa with submucosal expansion by fibroconnective tissue. Histological analysis demonstrated features of a prominent submucosal vascular component with dilated lymphovascular structures, the absence of inflammatory infiltrate and the absence of significant architectural disturbance (Figure 4). These findings were consistent with a diagnosis of a muco-submucosal elongated polyp.1, 2 Muco-submucosal elongated polyp of the GIT under white light. Muco-submucosal elongated polyp of the GIT under narrow band imaging (NBI). Muco-submucosal elongated polyp of the GIT following resection. Histology section (2X) through the polyp shows architecturally normal small intestinal mucosa (yellow arrow) overlying a core of submucosa containing abundant adipose tissue (blue arrow) with submucosal vessels (green arrows). No significant inflammation is seen. Enteric muco-submucosal elongated polyps are rare, benign gastrointestinal polyps with an elongated, cylindrical ‘worm-like’ endoscopic appearance that is a hallmark of the disease.2, 3 Initially identified in the colon,1 few cases have been reported in the small bowel.3 It is hypothesised that peristaltic movements serve as mechanical traction for redundant mucosa, creating a nidus for polyp growth in these mucosal areas. They can mimic a number of other enteric lesions, in particular prolapsing mucosal folds (associated with diverticular disease) and filiform polyps (associated with inflammatory bowel disease). Immunohistochemistry demonstrates positivity for endothelial vascular markers (CD31) and endothelial lymphatic vessels (D2-40/podoplanin). Endoscopic ultrasound (EUS) can demonstrate the mucosal and submucosal layers of the polyp, with characteristic microcystic components aiding the diagnosis. Symptomatic patients can be treated by endoscopic resection, although treatment may be considered in asymptomatic cases given case reports suggesting an associated risk of intussusception,4 diverticulitis5 and non-polypoid neoplasia.6, 7 Surveillance gastroscopy 3 and 12 months post resection did not reveal any residual polyps. The authors wish to acknowledge the patients who attend, and staff who work in the Endoscopy Unit and the contribution they make to clinical research. There was no funding source for this research. The authors have no conflicts of interest to declare. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.