Microscopic Gastritis: A Case Series Highlighting the Diagnostic and Therapeutic Challenges

Introduction: Microscopic colitis is a well-described entity, but there are limited data regarding microscopic gastritis. This case series highlights 3 cases of microscopic gastritis that are unique in presentation and therapy, which underscores the diagnostic challenges and lack of standardized treatment. Case 1: Collagenous Gastritis A 33-year-old woman presented with one year of abdominal pain and constipation. EGD showed diffuse friability and nodularity in the stomach (Figure 1A). Biopsy showed collagenous gastritis (Figure 1B). Celiac serologies were negative and duodenal biopsies were normal. She improved with a prednisone taper.Figure 1: (A) EGD showing stomach with diffuse nodularity with friability and mucosal oozing when biopsied. (B) Gastric biopsy demonstrating thickened subepithelial collagen layers on trichrome stain along with entrapped inflammatory cells.Case 2: Collagenous Gastritis, Enteritis, Colitis A 59-year-old woman presented for second opinion regarding treatment of her Crohn’s disease (CD). Pathology revealed no CD, rather collagenous gastritis, enteritis and colitis. Celiac serologies were negative. Adalimumab, mesalamine, and prednisone were discontinued. She improved with budesonide. Case 3: Lymphocytic Gastritis/Colitis and Sprue-Like Enteritis A 79-year-old woman presented with chronic diarrhea and weight loss for 6 months. EGD and colonoscopy were grossly normal, but duodenal biopsies strongly suggested celiac sprue. Gastric and colonic biopsies showed lymphocytic gastritis and colitis. Despite negative celiac serologies, a gluten free diet (GFD) was recommended. Subsequent HLA typing was negative, the GFD was stopped, and symptoms remitted with budesonide. Microscopic gastritis represents a wide range of clinical entities that may be under-recognized or misdiagnosed. Treatment varies but usually includes steroids. Budesonide has limited systemic absorption and specific pH requirements for release. Further investigation should help to validate a standard regimen of care for various disease distributions.