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IBD Biopsies

Guidelines on Inflammatory Bowel Disease Biopsies 2013

Professor Roger M Feakins

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.

Initial Biopsy Diagnosis of Suspected Chronic Idiopathic Inflammatory Bowel Disease 1997 (ARCHIVED)

Introduction

Unambiguous interpretation of colorectal biopsy specimens is important for clinical decisions in the investigation of suspected chronic idiopathic inflammatory bowel disease (IBD). Variability of reporting style and terms such as mild inflammatory change and non-specific proctitis/colitis may hide pathologists' difficulties with diagnostic uncertainty and confuse clinical management. Four main problems underlie these difficulties:

  • lack of awareness of the range of normal colorectal histology and the minimal features which indicate clinically important inflammation;
  • wide overlap in the pathological changes of most large bowel inflammatory diseases;
  • lack of awareness of the accuracy and reproducibility of many changes used in diagnosis; and
  • absence of standard terminology for pathological description and diagnosis.

On behalf of the British Society of Gastroenterology, we have used an evidence-based approach to compile guidelines for the biopsy diagnosis of suspected chronic idiopathic IBD.

The guidelines are aimed primarily at improved accuracy of diagnosis when colorectal biopsy is used in the initial investigation of patients with diarrhoea. The objectives are to assist: the recognition of normal colorectal mucosa; the detection of important minor inflammatory change needing further investigation; the early diagnosis of chronic idiopathic IBD; the distinction between ulcerative colitis and Crohn's disease; the recognition of infec tive type colitis; and the diagnosis of less frequent forms of colitis. The guidelines include recommendations for minimum clinical information, useful morphological features, standardised terminology, and a clinically relevant reporting format. The evidence is from Europe and North America, and the conclusions should not be applied uncritically where the prevalence and the nature of the diseases are very different.

Amendment:
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A Structured Approach to Colorectal Biopsy Assessment 1997 (ARCHIVED)

Introduction

These practical notes supplement the "Guidelines for the initial biopsy diagnosis of suspected chronic inflammatory bowel disease. The British Society of Gastroenterology Initiative", published in the Journal of Clinical Pathology and circulated to members of the BSG. They are directed at histopathologists assessing colorectal biopsies for suspected intestinal inflammation, and provide a detailed, structured approach to routine biopsy assessment to extract maximum diagnostic information from biopsies. The colorectal mucosa has a limited repertoire of responses to injury, and the similarity of pathological changes in ulcerative colitis, Crohn's disease and other intestinal inflammation causes considerable diagnostic confusion and uncertainty. Effective management, however, depends on accurate clinico-pathological classification, and it is hoped by following the scheme adopted here errors can be minimised. The evidence-base, consensus development, clinical and histological principles have been presented in the Guidelines. This supplement draws heavily on detailed descriptions of CIIBD and its pathological mimics by many authors. Extensive references are included in the Guidelines and are not repeated here. The use of references and updating the structured approach through literature searching and critical review should be part of the routine practice of evidence-based pathology.

The structured approach provides five questions to be answered, four biopsy "compartments" to be examined, detailed checklists for answering the questions, and guides to assessment of the answers. The diagnostic value of the various histopathological features to be assessed follows the grading in the Guidelines.