Collagenous gastritis: A case report, morphologic evaluation, and review

Collagenous gastritis is rare; there are only four previous case reports. H istologic features seem to overlap with the other "collagenous enterocoliti des"; however, pathologic criteria are not yet established for the diagnosi s of collagenous gastritis, We describe an additional case of ostensible co llagenous gastritis in a patient who initially presented with celiac sprue and subsequently developed colonic manifestations of mucosal ulcerative col itis. Endoscopic biopsies of the stomach revealed deposition of patchy, ver y thick bandlike subepithelial collagen in gastric antral mucosa, focal sup erficial epithelial degeneration, numerous intraepithelial lymphocytes, and a dense lamina propria lymphoplasmacytic infiltrate. Image analysis evalua tion of gastric antral biopsies demonstrated a mean thickness of subepithel ial collagen of 27.07 mu. Morphologic comparison was made with age-matched control groups of 10 patients who had normal gastric mucosal biopsies and 1 0 patients who had "chronic" gastritis, which revealed mean subepithelial c ollagen measures of 1.37 mu and 1.19 mu, respectively. We compared these mo rphologic findings with those of all previous case reports of collagenous g astritis and propose a pathologic definition based on the limited combined data. It seems that subepithelial collagen is dramatically thickened in rep orted cases of collagenous gastritis, with a cumulative mean measure of 36. 9 mu. It is also apparent from this and previous reports that the thickened subepithelial collagen is accompanied by a chronic or chronic active gastr itis and sometimes intraepithelial lymphocytes and surface epithelial damag e. Recently described associations of lymphocytic gastritis, sprue, and lym phocytic colitis as well as collagenous and lymphocytic colitis suggest a c ommon pathogenesis that empirically may include collagenous gastritis in th e same disease spectrum. We propose that collagenous gastritis can be confi dently identified by using analogous defined features of collagenous coliti s: subepithelial collagen more than 10 mu in a patchy distribution, lamina propria lymphoplasmacytic infiltrates, intraepithelial lymphocytes, and sur face epithelial damage. Collagenous gastritis also seems to have the same s pectrum of associated clinical findings as collagenous colitis, including f requent coexistence of celiac sprue, watery diarrhea syndrome, and female p redominance.