Collagenous gastritis: an unusual association with profound weight loss.

Collagenous gastritis is a distinctive disorder characterized by thickening of the subepithelial collagen layer in the gastric mucosa. Although this entity was recognized in 1989, its etiology, pathogenesis, and clinicopathologic features remain poorly understood because of its rarity. An unusual case of collagenous gastritis was observed in a 37-year-old man who presented with profound weight loss, a feature that has not previously been emphasized.