Barnacle-like lesions in the gastric mucosa: Clinicopathological study of a novel endoscopic finding.

Background and study aims: Map-like redness is a known gastric mucosal finding observed after Helicobacter pylori eradication. Recently, we identified gastric lesions resembling barnacles and observed that they appear more commonly in cases of post- H. pylori infection. This study aimed to investigate clinicopathological characteristics of these barnacle-like lesions.

Patients and methods: We analyzed clinical characteristics in 436 consecutive patients examined at Kawasaki Medical School General Medical Center. Histopathological examination was conducted in 43 patients, with 65 biopsies taken from barnacle-like lesions and 17 from the surrounding mucosa. The 43 patients comprised 20 patients biopsied at General Medical Center and 23 patients at Junpukai.

Results: In total, 413 patients (208 women) were included in the analysis after excluding 23 patients based on exclusion criteria. Barnacle-like lesions were identified in 66 patients (16.0%), most frequently around the gastric angle, and were significantly more common in patients with mild atrophy of the fundic mucosa. Of the 66 patients with barnacle-like lesions, 65 were considered to have a post- H. pylori infection status and one was currently infected. Histopathological examination revealed intestinal metaplasia in 54 (83.1%) of the 65 biopsies from barnacle-like lesions. By contrast, all 17 biopsies from surrounding mucosa showed normal fundic mucosa without inflammation or atrophy.

Conclusions: Barnacle-like lesions are a characteristic endoscopic finding of gastric mucosa post-infected with H. pylori and are histopathologically consistent with intestinal metaplasia.