Collagenous gastritis.

A 25-year-old patient presented with epigastric pain, which on gastric biopsy revealed the characteristic appearance of collagenous gastritis. There was a thick prominent subepithelial band that was confirmed to be collagen with a Masson's trichrome stain. There was associated Helicobacter pylori gastritis but no evidence of a lymphocytic gastritis. The patient did not have watery diarrhea. Collagenous gastritis can occur in young patients, be restricted to the stomach, and can be associated with celiac disease.