A gastric wall abscess is a type of phlegmonous gastritis characterized by inflammation confined to the stomach wall and abscess formation. It is caused by biopsy, polypectomy, cancer and accidental ingestion of foreign objects [1]. Endoscopic drainage has been considered useful [2]. No case of spontaneous alleviation of gastric wall abscess has been reported previously. A 57-year-old man with no previous medical history swallowed a fish bone (flounder). The next day, he complained of epigastric discomfort and fever. He came to our hospital 10 days after the onset of the symptoms, and upper gastrointestinal endoscopy was performed. A submucosal tumor (SMT)-like protrusion was observed in the anterior wall just below the stomach cardia, as well as pus discharge from the top of the lump (Fig. 1A). Contrast-enhanced computed tomography revealed fluid collection in the gastric wall (Fig. 2), and these findings were consistent with that of gastric abscess. On the next day, endoscopy revealed that the protrusion suspected as a gastric wall abscess had clearly shrunk, but pus discharge was observed (Fig. 1B). Endoscopic ultrasound (EUS) showed inhomogeneous lesion of mixed echogenicity located mainly in the submucosal layer with mucosal involvement (Fig. 1C), consistent with the reported features of EUS of gastric wall abscess [3]. Streptococcus spp. was detected on pus culture. Three days after, the subjective symptoms had completely alleviated; the SMT-like protrusion had further shrunk, as observed via endoscopy. The SMT-like protrusion was not observed via upper endoscopy performed 1 month after discharge (Fig. 1D).
Figure 1 Endoscopic view of gastric wall abscess. (A) A submucosal tumor-like protrusion was observed below the stomach cardia with pus discharging. (B) Protrusion had clearly shrunk on the next day. (C) Radial endoscopic ultrasound image demonstrated inhomogeneous lesion of mixed echogenicity in gastric wall. (D) There was no residual lesion one month later
Figure 2 Computed tomography scan showed a large, hypo-dense, tumor-like lesion just below the stomach cardia