Collagenous gastritis associated with lymphocytic colitis.

Collagenous sprue and collagenous colitis are two well-recognized idiopathic enteritides whose defining histologic attribute is fibrous thickening of the subepithelial basement membrane. Analogous changes in gastric mucosa seem to be quite rare. The term "collagenous gastritis" was recently applied for the first time to an isolated case of refractory gastritis in which distinctive subepithelial gastric fibrosis was noted. We report an additional case of this entity in a 35-year-old woman with refractory dyspepsia. In contrast to the earlier case of collagenous gastritis, our patient also had lymphocytic colitis, a type of colitis associated with watery diarrhea. Collagenous gastritis appears to be a distinct clinicopathologic entity, the histologic changes of which should be sought in patients with unexplained dyspepsia. Increased awareness of this condition and its possible clinical correlates may provide clues to its etiology and pathogenesis.