S3386 An Unusual Site for a Rare Colonic Polyp

Abstract

INTRODUCTION: Colonoscopy has been the best tool for screening of colorectal diseases. The increasing use of colonoscopy has led to the finding of more abnormalities along the gastrointestinal tract. The most common finding lesions are of epithelial origin, such as hyperplastic and adenomatous polyps. Less common are subepithelial lesions, such as leiomyomas. Leiomyomas, often solitary, can present anywhere along the gastrointestinal (GI) tract, most commonly in the esophagus and stomach, while colonic leiomyomas are rare, accounting for less than 3% of all GI leiomyomas. CASE DESCRIPTION/METHODS: A 52-year-old nonsmoker man presents to his screening colonoscopy appointment with complaint of intermittent watery non-bloody diarrhea, occurring after meals, for 3 weeks. He denied abdominal pain, fevers, chills, weight loss, nausea, vomiting, and diet changes. Physical examination and laboratory tests were unremarkable. Few days later, patient underwent esophagogastroduodenoscopy (EGD) revealing mild superficial inflammation of the gastric body and antrum, positive for Helicobacter pylori. On colonoscopy, a 6mm hard single smooth surfaced non-pedunculated polyp at the descending colon was found, clipped, and biopsied. Immunohistochemistry was positive for smooth muscle actin and desmin, confirming the diagnosis of leiomyoma of the submucosa. Patient reported resolution of symptoms, and was recommended repeat colonoscopy in five years. DISCUSSION: There are not many reported cases of colonic leiomyomas. To the best of our knowledge, this is the first reported case of leiomyoma found at the descending colon. Colonic leiomyomas are largely asymptomatic, and found incidentally. However depending on the size and location, colonic leiomyomas may cause abdominal pain, intestinal obstruction, hemorrhage and perforation. With increases in screening colonoscopies, more reports of colonic leiomyomas are expected to be identified, thereby making it important to be aware of such a rarely reported benign lesion, as it may be confused with more malignant lesions. Traditionally, colonic leiomyomas were surgically resected because the risk of perforation was higher with endoscopic procedures. With current advances and developments in endoscopic techniques, endoscopic ultrasonography is becoming the best diagnostic and treatment tool for submucosal lesions. In this presenting this case, our goal is to provide guidance in the diagnosis of colonic leiomyomatous polyps.Figure A.: One 6 mm single, hard smooth non-bleeding polyp found in the descending colon during colonoscopy.Figure B.: Post-resection of polyp found in the descending colon via cold forceps, blood loss minimal, For Hemostasis, one hemostatic clip was applied.Figure C.: Slide of descending colon polyp illustrating the spindle-shaped smooth muscle cells, and part of the mucosa at low magnification (H&E x40).