Anisakis with a Gastric Ulcer after Endoscopic Resection

A 67-year-old man was referred to our hospital for treatment of gastric adenocarcinoma of the fundic gland type located in the greater curvature of the gastric body (Picture 1a). He underwent endoscopic submucosal dissection (ESD), and the lesion was resected en bloc without any adverse events (Picture 1b). The histopathological diagnosis was gastric adenocarcinoma of the fundic gland type: M, Gre, 38×28 mm, type 0-IIc, 10×7 mm, tub2>tub1, pT1a (M), pUL0, Ly0, V0, pHM0, and pVM0, according to the Japanese classification of gastric cancer 15th edition (Picture 2). Two months after ESD, follow-up endoscopy was performed. A nematode was found on an artificial ulcer resulting from the ESD; it was removed with forceps (Picture 1c, 1d) and histologically confirmed to be an Anisakis larva (Picture 3). The patient had eaten raw Yellowtail fish three days before his hospital visit but had no symptoms, such as abdominal pain. Anisakis is caused by raw seafood ingestion, often leading to adverse situations, such as perforation, although the present case was uneventful. There have been reports that Anisakis can cause gastric ulcers (1) and that it prefers to attach to digestive cancers (2), but there have been no previous reports of Anisakis attaching to artifi-