1483 Full Thickness Resection Device for the Removal of a Submucosal Sigmoid Carcinoid Tumor

Abstract

INTRODUCTION: Colonic neuroendocrine tumors (NETs) are rare neoplasms, but they carry the worse prognosis. Management of these tumors is difficult and may result in repeated interventions and prolonged surveillance. Endoscopic Full Thickness Resection (FTR) is not currently included in the guidelines for management of NETs. This case describes a technically and histologically successful FTR of a sigmoid goblet cell carcinoid tumor. CASE DESCRIPTION/METHODS: A 61-year-old male presents for screening colonoscopy and was found to have an 8 mm submucosal mass in the distal sigmoid. Pathology of biopsies showed hyperplastic colonic mucosa with marked reparative stromal and epithelial changes and mixed features of prolapse. He was referred to our institution for EUS of the submucosal lesion, which revealed hypoechoic submucosal lesion in distal sigmoid measuring 7.4 × 4.7 mm. FNA was attempted but unsuccessful as the mass was small and mobile. Therefore, decision was made to perform endoscopic mucosal resection (EMR). Pathology on EMR of sigmoid lesion revealed goblet cell carcinoma. Deep and lateral margins were positive. Chromogranin A level was mildly elevated. He was referred to surgical oncology who recommended 3 month surveillance colonoscopy given low Ki index. CT Scan of Abdomen and Pelvis as well as Octreotide scan were both negative for distant metastases. At 3-month follow up colonoscopy, the decision was made to use Full Thickness Resection Device (FTRD) of the sigmoid lesion given positive margins. Pathology of FTRD was consistent with neural sheath tumor and deep and lateral margins were negative. Repeat colonoscopy revealed well healed scar at site of FTRD and cold biopsies around the scar were benign. He will follow up in 3 years for repeat colonoscopy. DISCUSSION: Primary colonic neuroendocrine tumors are rare but are generally more aggressive and carry the worst prognosis dependent on stage. Current consensus guidelines for the management of local regional NETs recommend endoscopic resection via polypectomy, EMR or endoscopic submucosal dissection. There have only been a few reported cases of the use of FTRD to treat submucosal carcinoid tumors in the colon. Success rates for endoscopic full thickness resection of gastric tumors has been described in the literature with success rates of up to 100%. High success rates of FTRD on colorectal lesions, not NETs, have also been noted. Given this, FTRD should be considered as a more definitive modality for treatment involving submucosal carcinoid tumors.