Sessile serrated lesion presenting as large pedunculated polyp in the rectum: A case report

Sessile serrated lesions (SSLs) are serrated polyps (SP) with the typical serrated architecture of the crypt lining epithelium. SSL has an important clinical implication because they are recognized as precursor lesion of sporadic colorectal cancer (CRC) through “serrated pathway.” SSLs usually appear flat to sessile, and are located in the right colon. PATIENT CONCERNS: A 69-year-old man was referred to a tertiary medical center because of intermittent hematochezia for 2 years. DIAGNOSIS: Colonoscopy revealed a large, pedunculated polyp in the rectum. The polyp surface was slightly reddish in color and the elongated stalk was covered with almost normal mucosa. Histopathological examination of the resected specimens revealed the typical features of SSL with low-grade dysplasia. INTERVENTION: Endoscopic mucosal resection using a detachable snare was performed on the tumor for definite diagnosis and treatment. OUTCOMES: There was no evidence of immediate or delayed bleeding after endoscopic mucosal resection, and the hemoglobin level normalized after a 1-year follow-up. LESSONS: We report a rare case of a large pedunculated polyp with typical histological features of SSLs in the rectum. Endoscopists should always consider SSLs at any location even with unusual morphological findings.