Gastrointestinal: Gastric anisakiasis presenting as a submucosal tumour diagnosed by endoscopic submucosal dissection

Abstract

We report a case of gastric anisakiasis presenting as a submucosal tumour that was completely resected by endoscopic submucosal dissection. A 55-year-old woman without an obvious history of raw-fish consumption or severe abdominal pain was referred to our hospital for a comprehensive examination of a gastric submucosal tumour detected by barium gastrography. Gastroscopy revealed a 2 cm diameter submucosal tumour at the greater curvature of the gastric mid-body (Figure 1A). Endoscopic ultrasound (EUS) revealed a heterogeneous hypoechoic mass with a hyperechoic core (Figure 1B). The lesion occupied the submucosa and muscularis propria. The possibility of a malignant tumour could not be excluded, because the tumour was newly identified and showed a heterogeneous pattern on the EUS images. ESD was performed after obtaining the patient's informed consent 3 months after the initial gastroscopy. Submucosal dissection during ESD was difficult because of severe fibrosis. The submucosal tumour was completely resected but complicated by a tiny perforation, which was managed by application of endoclips. Pathological examination of the lesion revealed a granulomatous lesion with prominent eosinophilic infiltration and a lumen-like structure consistent with the characteristics of gastric anisakiasis (Figure 2A,2B). Contributed by