COLLAGENOUS GASTRITIS ASSOCIATED WITH GASTRIC PERFORATION

Abstract

Purpose: Collagenous gastritis (CG) is an exceptionally rare clinicopatho-logic entity of unknown etiology characterized by thickening of the subep-ithelial collagen layer in the gastric mucosa. We report the first case of CG associated with gastric perforation. An 18-year-old male was referred following two perforated gastric ulcers. He had undergone patch repair following the first and partial gastrectomy with highly selective vagotomy following the second perforation. EGD revealed nodular erythema involving the proximal stomach. Biopsy revealed active chronic gastritis with no H. pylori. Evaluation for known etiologies of gastritis was unrevealing. Gastric acid analysis: 1 hour basal acid 0.91 m Eq/L, gastrin level, small bowel biopsy-normal, endomysial antibody-negative. EGD a year later showed persistent nodularity and biopsy revealed a thick layer of sub-epithelial collagen confirmed by trichrome staining (figure 1). Therapy with Bismuth subsalicylate resulted in no endoscopic or histologic improvement. Colonic biopsies were normal.FigureFirst described in 1989, less than 20 cases of CG have been reported. It is defined histologically by presence of a thickened subepithelial collagen band at least 10 μm in thickness with an inflammatory infiltrate of the lamiNaPropria. Some of the reported cases were associated with celiac disease, collagenous and lymphocytic colitis. The distribution of this band tends to be irregular, which may explain the delay in diagnosis in our patient. The pathogenesis remains obscure and no effective therapy has been described. Postulated pathogenetic theories include autoimmune injury and local abnormality of peri-cryptal collagen with leakage of plasma proteins and subsequent replacement with collagen. None of the reported cases were associated with perforation. Encasement of sub-epithelial blood vessels by collagen, as seen in our patient, could result in gastric mucosal ischemia making it more susceptible to acid related injury. Physicians should be aware of this entity during routine examination of gastric biopsies. CG should be considered in the differential diagnosis of unexplained H. pylori negative chronic gastritis. [figure 1]