Special Considerations in Pediatric Inflammatory Bowel Disease Pathology

Abstract

Inflammatory bowel disease (IBD) in the pediatric population presents distinct characteristics compared to adult cases. Pathology plays a critical role in its diagnosis, and this review underscores key considerations in the pathologic evaluation of pediatric IBD. Recognizing inflammatory patterns in the upper gastrointestinal tract can improve disease classification and aid in diagnosing IBD in certain scenarios, such as isolated upper gastrointestinal or small bowel involvement. Additionally, familiarity with distinctive subtypes, including IBD associated with primary sclerosing cholangitis and monogenic forms of IBD, supports early comorbidity detection, enhances patient management, and improves prognostication.

Keywords: Crohn disease; PSC-IBD; focally enhanced gastritis; lymphocytic esophagitis; monogenic; ulcerative colitis.

Figure 1

Upper gastrointestinal (GI) manifestations in pediatric inflammatory bowel disease (IBD) include (A) lymphocytic esophagitis, characterized by an increased number of intraepithelial lymphocytes with dilated intercellular spaces and parakeratosis (H&E, 4×). (B,C) Focally enhanced gastritis, marked by focal inflammation (white arrow) in the corpus mucosa, with neutrophilic infiltrates and associated epithelial injury (H&E, 4× and 20×). Notably, there is no significant background of chronic inflammation. (D) Brunner gland lobulitis in a patient with Crohn disease, showing focal acute inflammation involving mucosal Brunner glands (H&E, 10×). (E) Non-necrotizing granulomas, which most frequently affect the stomach in the upper GI tract, illustrated by antral mucosal involvement in a patient with Crohn disease (H&E, 10×). (F) Helicobacter infection should be ruled out in biopsies showing chronic active or inactive gastritis, as it may coexist with IBD (H&E, 10×). Microorganisms consistent with Helicobacter pylori are identified on H&E staining (white arrow and inset, H&E, 20×).

Figure 2

Chronic granulomatous disease is characterized by (A) an epithelioid granuloma in the lamina propria of the colonic mucosa (H&E, 10×) and (B) pigmented macrophages (white arrows; H&E, 20×). There is no significant active inflammation or chronicity in this colonic mucosa.