S1772 A Giant Hyperplastic Colorectal Polyp With No Malignant Features

Abstract

Introduction: Hyperplastic polyps (HP) are a benign subgroup of serrated polyps. HP larger than 10 mm is considered a large polyp and larger than 2 cm carry a risk for malignancy. A case of near obstructing giant hyperplastic polyp of the recto-sigmoid colon with no malignant features is presented with a topic review and proposed further follow-up. Case Description/Methods: A 29-year-old African American man presented to the gastroenterology clinic with a 1-year history of early satiety, intermittent rectal bleeding, alteration in bowel habits, and weight loss. Upper and lower endoscopies identified a large pedunculated mass with near-complete obstruction in the recto-sigmoid colon [Figure 1A]. Biopsies show hyperplastic mucosa with no evidence of a malignant process. Imaging revealed distal colonic mass extending over a 6 cm segment [Figure 1B]. CEA and cancer antigen CA 19-9 markers were unremarkable. Laparoscopic sigmoid resection was performed. Histology reported pedunculated polyp 2.5 x 2.5 x 1.8 cm and 2 cm stalk with serrated appearance, hyperplasia, and no evidence of malignancy [Figure 1C]. Postoperative course was uneventful, with improvement in appetite and weight gain. Genetics evaluation deferred further testing. Discussion: HP are the most abundant type and now believed to be a subgroup of serrated polyps (SP). SP are classified into two main subgroups based on malignant potential. The majority of the serrated carcinomas arising from HP follow BRAF and KRAS pathways. Microsatellite instability has also been associated [1]. Serrated polyposis syndrome is associated with the risk of colorectal cancer. Due to the inability of subtracting a single responsible gene, other syndromes should be excluded. Polyps larger than 1 cm are classified as large, and exceeding 3 cm as a giant. Parallel to the size increases the malignant potential. Risk stratification of giant, pedunculated polyps is advised prior to endoscopy due to the risk of perforation and bleeding. Due to the concern for malignant transformation with obstructive signs and symptoms, surgical excision was advised.Further discussions are needed to establish clear guidelines for testing and surveillance of single giant non-malignant polyps. We propose our own management including surgical vs. endoscopic resection, genetic testing, and colonoscopy in 1,3, and 5- year intervals, followed by standard surveillance.Figure 1.: A. Abdominal CT scan. B. Colonoscopic view. C. Lower Endoscopic Ultrasound View. D. Histopathology.