1554 An Unusual Cause of Hematochezia: Anorectal Inflammatory Myoglandular Polyp

Abstract

INTRODUCTION: Colorectal polyps are an unusual cause of hematochezia and usually result from overlying ulcerations on adenomas or cancers. Non-adenomatous polyps, such as inflammatory polyps, may be a rare cause of gastrointestinal bleeding. Here, we present a case of a patient with painless hematochezia found to be originating from a bleeding anorectal inflammatory myoglandular polyp related to rectal prolapse. CASE DESCRIPTION/METHODS: A 51-year-old man with alcohol abuse and hepatitis C presented with fatigue and light-headedness along with 7-8 years of small volume painless hematochezia with bowel movements. He endorsed straining with bowel movements and something protruding from his anus that he would push back in. On physical exam, he was hemodynamically stable with a normal abdominal exam and a rectal exam revealing a palpable rectal mass without overt signs of bleeding. His lab work was notable for a hemoglobin of 5.5 g/dL. Magnetic resonance imaging (MRI) of the pelvis revealed rectal wall thickening and an enhancing mass abutting the anal sphincter (Figure 1). Colonoscopy revealed left-sided diverticulosis without bleeding and an ulcerated, vascular mass in the anal canal, best seen on retroflexion (Figures 2 and 3). Biopsies of the mass were consistent with an inflammatory myoglandular polyp thought to result from intermittent rectal prolapse. The mass was resected via transanal excision with complete resolution of hematochezia. DISCUSSION: Inflammatory myoglandular polyps are rare, non-neoplastic pedunculated polyps that are predominantly incidental findings during enemas or endoscopy but can present with hematochezia. While concentrated mostly in the distal colon, they can be seen in the descending and transverse colon as well. The etiology remains unknown, but there may be an association with mucosal prolapse and sigmoid diverticulosis. Specifically, it is hypothesized that chronic trauma from intestinal peristalsis may distort colonic crypt architecture, which results in muscularization of the lamina propria. This leads to subsequent redundancy and passive venous congestion that contributes to prolapse of these lesions. Generally, symptomatic inflammatory myoglandular polyps require endoscopic or surgical resection, which is curative. In this case, given the patient's symptoms along with the size and location, surgical management was indicated.