Endoscopic submucosal dissection for a large (exceeding 3 cm) exophytic gastric schwannoma with 24-hour intragastric retention: a case report and brief literature review.

BACKGROUND: The clinical role of endoscopic resection in the treatment of exophytic gastric schwannomas measuring ≥3 cm remains controversial owing to technical difficulties and a paucity of evidence. CASE PRESENTATION: A 58-year-old female patient was admitted for treatment after a gastric mass was discovered during routine physical examination. Endoscopic ultrasonography (EUS) revealed a well-demarcated, hypoechoic submucosal tumor measuring 40.9×32.3 mm. The patient subsequently underwent endoscopic submucosal dissection (ESD) under general anesthesia. Histopathological analysis confirmed the diagnosis of gastric schwannoma, with immunohistochemical staining showing strong S-100 protein positivity. The patient had an uneventful recovery with no procedure-related complications, and there has been no evidence of recurrence to date. CONCLUSION: While this single-case experience indicates the technical feasibility of ESD for gastric schwannomas >3 cm, larger-scale prospective studies are required to establish its role in clinical practice.