Collagenous gastritis in a young Japanese woman.

Collagenous gastritis, a counterpart of collagenous colitis, is a rare disorder with less than 20 cases reported in the literature. A case of collagenous gastritis in a Japanese woman in her early 20s who had been receiving treatment for atopic dermatitis and bronchial asthma is reported. The patient complained of repeated epigastric pain, and endoscopy revealed multifocal atrophic areas and scars in the gastric body. Biopsy specimens showed a thickened eosinophilic band-like structure with entrapped capillaries approximately 30-70 micro m thick beneath the surface epithelium. It was regarded as a collagen band because it was positive on Azan staining but negative on amyloid staining. This finding was accompanied by marked infiltration of mononuclear cells and eosinophils in the lamina propria; however, no evidence of lymphocytic gastritis was found. Helicobacter pylori infection was not detected and inflammatory cell infiltration was minimal in the mucosa without the collagen band. Immunohistochemical analysis revealed that the band was positive for type III and type VI collagen. The size of the collagen band did not change for 2 years. These findings suggest that subepithelial collagen deposition was due to an abnormal local immune response based on generalized allergic disorder.