Inflammatory bowel disease biopsies: updated British Society of Gastroenterology reporting guidelines

Abstract

Accurate histopathological assessment of biopsies is important for the diagnosis, subclassification, and management of chronic idiopathic inflammatory bowel disease (IBD). British Society of Gastroenterology (BSG) guidelines for the initial histopathological diagnosis of IBD were published in 1997. Changes since then include: more widespread use of full colonoscopy; greater recognition of the effects of time and treatment; improved documentation of variations in anatomical distribution; better understanding of the mimics of IBD; significant progress in clinical management; and modifications of terminology. Accordingly, an update is required. These revised guidelines aim to optimise the quality and consistency of reporting of biopsies taken for the initial diagnosis of IBD by summarising the literature and making recommendations based on the available evidence. Advice from existing clinical guidelines is also taken into account. Among the subjects discussed are: distinguishing IBD from other colitides, particularly infective colitis; subclassification of IBD (as ulcerative colitis, Crohn's disease, or IBD unclassified); the discriminant value of granulomas; aspects of disease distribution, including discontinuity in ulcerative colitis; time-related changes; differences between paediatric and adult IBD; the role of ileal and upper gastrointestinal biopsies; differential diagnoses such as diverticular colitis and diversion proctocolitis; and dysplasia. The need to correlate the histological features with clinical and endoscopic findings is emphasised. An approach to the conclusion of an IBD biopsy report based on the acronym Pattern, Activity, Interpretation, Dysplasia (PAID) is suggested. The key recommendations are listed at the end of the document.

Pseudomembranous collagenous colitis: an unusual cause of chronic diarrhoea

“…Recent guidelines published by the British Society of Gastroenterology highlight the importance of biopsy technique and clinical correlation 5. They emphasise the significance of taking biopsies from multiple sites in the colon and the relevance of multidisciplinary meetings in order to discuss the findings.…”

Guía práctica para el diagnóstico de displasia y de carcinoma colorrectal en la enfermedad inflamatoria intestinal

“…La guía británica no recomienda el empleo de técnicas inmunohistoquímicas para el diagnóstico de DE, aunque reconoce que pueden en ocasiones ayudar a corroborar un diagnóstico 10 .…”

“…La interpretación de las biopsias exige experiencia, recomendándose la confirmación diagnóstica por un segundo patólogo 6 , especialmente en aquellos casos que afecten de forma importante al manejo del paciente. Las biopsias deben interpretarse conociendo las historias, clínica y morfológica del paciente 10,11 .…”

Managing inflammatory bowel disease in adolescent patients

“…A small number of individuals diagnosed with IBD, including adolescents, will have endoscopic and histologic findings at the time of diagnosis that do not differentiate between UC and CD: the term IBD-unclassified (IBDU) should be used for this situation 6,7. Generally, with the passage of time and the evolution of the pattern and features of inflammation, IBDU is able to be reclassified as CD or UC 6,7. One report indicated that IBDU is reclassified as UC more commonly 8.…”