Ulcerative colitis or Crohn's disease? Pitfalls and problems

Abstract

The interpretation of colorectal biopsies taken for the initial diagnosis of chronic idiopathic inflammatory bowel disease (IBD) is challenging. Subclassification of IBD as ulcerative colitis (UC) or Crohn's disease, which may be particularly difficult, is the subject of this review. Biopsies taken at first presentation are emphasised, partly because their features have not been modified by time or treatment. Aspects of longstanding disease and of resections are also mentioned. The first part of the review comprises background considerations and a summary of histological features that are discriminant, according to published evidence, between UC and Crohn's disease in initial biopsies. Pitfalls and problems associated with making the distinction between UC and Crohn's disease are then discussed. These include: mimics of IBD; inadequate clinical details; unreliable microscopic features; absence of histological changes in early IBD; discontinuity in UC; cryptolytic granulomas; differences between paediatric and adult UC; reliance on ileal and oesophagogastroduodenal histology; and atypical features in IBD resections. Avoidance by pathologists of known pitfalls should increase the likelihood of accurate and confident subclassification of IBD, which is important for optimum medical and surgical management.

Immunopathogenesis of granulomas in chronic autoinflammatory diseases

“…The histological finding of a non-caseating granuloma is the most discriminating factor for Crohn's disease. 24 Supporting evidence from laboratory analyses include high C-reactive protein, low hemoglobin and high fecal calprotectin. 11 Furthermore, the majority of patients has detectable serum levels of anti- Saccharomyces cerevisiae antibodies, 25 or antibodies to the outer membrane porin C of Escherichia coli (anti-OmpC).…”

Integrating omics for a better understanding of Inflammatory Bowel Disease: a step towards personalized medicine

“…IBD is characterized by the repeated alternating cycles of clinical relapse and remission [2] and in the absence of an adequate treatment, a chronic inflammation leading to irreversible intestinal damages [3]. Based on the disease manifestation, IBD is classified into three major subtypes [4]: Ulcerative Colitis (UC), which primarily affects the colon, Crohn's disease (CD) which affects various GI sites [5], and a third subtype where histology assessments done on patients do not categorize to either UC or CD. This subtype is defined as "Inflammatory Bowel Disease, type unclassified" or "Undetermined" (IBD-U) [6,7].…”

An index with improved diagnostic accuracy for the diagnosis of Crohn's disease derived from the Lennard‐Jones criteria

“…The overall diagnostic value of the microscopic features lymphoid aggregates and discontinuous inflammation on histology was low and none of these made it into the model. In general, there are differences between interpretation of endoscopic biopsies and surgical specimens as well as inter‐observer disagreement on histopathological features . In addition, histological changes might be absent in early CD .…”

“…20 In addition, histological changes might be absent in early CD. 20 Conversely, granuloma is the most corroborating microscopic feature favouring CD over ulcerative colitis. Although it is assumed that granulomas are found only in a minority of CD biopsies there is some evidence that epitheloid cell granulomas are more frequent in early CD and might regress during the course of the disease and/or under treatment.…”