S2884 Successful Endoscopic Full Thickness Resection of a Submucosal Tumor: A Rare Result

Abstract

Introduction: Gastric adenomyoma (GA) is a rare submucosal tumor (SMT) often discovered incidentally. Historically it has been diagnosed and treated with surgical resection. Ours is the first reported case of a GA that was successfully removed via endoscopic full thickness resection (EFTR). Case Description/Methods: A 70-year-old Chinese man was incidentally found to have an intramural gastric antral mass on MR Abdomen. Subsequent esophagogastroduodenoscopy (EGD) and endoscopic ultrasound (EUS) confirmed presence of a heterogenous 14 mm submucosal nodule which was successfully removed via non-exposed EFTR. Pathology showed smooth muscle and glands consistent with benign GA with clear margins. No complications were noted on one-month follow-up. (Figure) Discussion: GA is a rare SMT usually found in the gallbladder but also described in the gastric antrum and pylorus. It may present as an incidental finding on cross-sectional imaging or endoscopy. Tumors >20 mm are associated with symptoms (epigastric pain, fullness). GA is usually benign, but cases with co-existing malignancy are reported in literature. Similar to our EUS findings, prior reported cases of GA show a submucosal nodule with heterogenous appearance. However due to paucity of data, EUS characteristics for GA are inadequate to differentiate it from malignant SMTs. Additionally, the malignant potential of small SMTs < 20 mm remains controversial and surgical resection is recommended for high risk lesions (heterogenous appearance, irregular borders, cystic spaces, echogenic foci). Techniques for endoscopic removal of SMTs have developed greatly over the last decade. SMTs < 40 mm have been successfully removed using EFTR without significant complications. Ours is the first reported case of a GA removed using EFTR. We recommend consideration of EFTR as an effective and less invasive alternative to surgical resection in small SMTs with high risk for malignant potential.Figure 1.: Imaging, endoscopic and pathologic findings of a gastric adenomyoma removed using endoscopic full-thickness resection.