Three case reports of collagenous gastritis in children: Lessons for an endoscopic and histologic approach to mucosal nodularity of the stomach

Abstract

Rationale: Collagenous gastritis (CG) is a rare form of chronic gastritis defined histologically by a thickened subepithelial collageneous band in the lamina propria. However, the clinical features and endoscopic findings of CG have not been clearly established in the pediatric population.

Presenting concerns: We report the cases of 3 children who presented with intractable anemia and minimal or no gastrointestinal (GI) symptoms and were followed up without definitive diagnosis determination even through diagnostic endoscopic evaluations.

Diagnoses: On repeated endoscopic examination, we determined thickened subepithelial collagen band, confirmed by Masson trichrome staining using targeted biopsies of the intervening mucosa between the prominent nodular lesions.

Interventions: Under the diagnosis of CG, a course of steroid was administrated in 1 patient, while all patients continued oral iron replacement therapy.

Outcomes: All 3 patients remained asymptomatic and their anemia was alleviated with continued administration of oral iron.

Main lessons: We recommend early endoscopic evaluation for patients with unexplained anemia, emphasizing a high index of suspicion for CG, despite the absence of definitive GI symptoms. Targeted gastric biopsies should be performed in the depressed mucosa surrounding the nodules, as well as the nodules themselves, to confirm CG, when presented with nodular gastric mucosa in endoscopy.

Figure 1

Esophagogastroduodenoscopic findings of the 3 patients. A, Initial endoscopy of patient 1 revealed diffusely nodular mucosa in the gastric body. B, The 6-month follow-up endoscopy of patient 1 demonstrated more prominent nodularity and multiple polypoid lesions with pale background mucosa. C, Initial endoscopy of patient 2 revealed coarsely nodular mucosa interspersed in the gastric body. D, The 20-month follow-up endoscopy of patient 2 demonstrated a striking nodularity of the gastric body. E, Initial endoscopy of patient 3 revealed edematous mucosa and multiple ulcerations with whitish mucus throughout the gastric antrum. F, The 7-month follow-up endoscopy of patient 3 demonstrated prominent nodularity on the gastric antrum.

Figure 2

Histopathologic examinations of the biopsy specimens. A, Biopsy taken from the intervening mucosa between polypoid lesions of patient 1 showed patchy deposition of collagenous tissue in the lamina propria, where the thickness was maximally 50.6 μm and eosinophilic infiltration is prominent (40–70 eosinophils/high power field, hematoxylin and eosin (H&E), ×400 magnification). B, A follow-up endoscopy with biopsy of patient 2 revealed focally fibrocollagenous deposition in the lamina propria with partial damage and detachment of the surface epithelium (H&E, ×400 magnification). C, A follow-up endoscopy with biopsy of patient 3 showed a subepithelial collagen band averaging 35 to 45 μm thickness with mild inflammation (H&E, ×200 magnification). D, Corresponding Masson Trichrome stain of the tissue of patient 1 showed a blue thick band of collagen in the subepithelial area measuring up to 43.8 μm in thickness (×400 magnification).