What Makes an Expert Barrett’s Histopathologist?

Assessment of epithelial dysplasia in ulcerative colitis has been hindered by inconsistencies in and disagreements about nomenclature and interpretation. To resolve these issues, pathologists from ten institutions participated in three exchanges of multiple slides and, following each exchange, in discussions of the results. A classification system for the epithelial changes that occur in ulcerative colitis was developed, which should be applicable to other forms of inflammatory bowel disease as well. The classification makes use of standardized terminology, addresses specific problem areas, and offers practical solutions. The reproducibility of the system was studied by means of examinations of both inter- and intra-observer variations. The clinical implications of the findings were incorporated into suggestions for patient management. The basis of the classification is that the term "dysplasia" is reserved for epithelial changes that are unequivocally neoplastic and may therefore give rise directly to invasive carcinoma. Specimens are categorized as negative, indefinite, or positive for dysplasia. The negative category includes all inflammatory and regenerative lesions and indicates that only continued regular surveillance is required. The indefinite category is applied to epithelial changes that appear to exceed the limits of ordinary regeneration but are insufficient for an unequivocal diagnosis of dysplasia or are associated with other features that prevent such unequivocal diagnosis. Clinically, it indicates that early repeat biopsy is often required to assess the changes more accurately. The positive category is divided into two subcategories: 1) high-grade dysplasia, for which colectomy should be strongly considered after confirmation of the diagnosis, and 2) low-grade dysplasia, which also requires confirmation and early repeat biopsy or colectomy, depending on other findings.

These guidelines provide a practical and evidence-based resource for the management of patients with Barrett's oesophagus and related early neoplasia. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument was followed to provide a methodological strategy for the guideline development. A systematic review of the literature was performed for English language articles published up until December 2012 in order to address controversial issues in Barrett's oesophagus including definition, screening and diagnosis, surveillance, pathological grading for dysplasia, management of dysplasia, and early cancer including training requirements. The rigour and quality of the studies was evaluated using the SIGN checklist system. Recommendations on each topic were scored by each author using a five-tier system (A+, strong agreement, to D+, strongly disagree). Statements that failed to reach substantial agreement among authors, defined as >80% agreement (A or A+), were revisited and modified until substantial agreement (>80%) was reached. In formulating these guidelines, we took into consideration benefits and risks for the population and national health system, as well as patient perspectives. For the first time, we have suggested stratification of patients according to their estimated cancer risk based on clinical and histopathological criteria. In order to improve communication between clinicians, we recommend the use of minimum datasets for reporting endoscopic and pathological findings. We advocate endoscopic therapy for high-grade dysplasia and early cancer, which should be performed in high-volume centres. We hope that these guidelines will standardise and improve management for patients with Barrett's oesophagus and related neoplasia.

Use of the conventional Western and Japanese classification systems of gastrointestinal epithelial neoplasia results in large differences among pathologists in the diagnosis of oesophageal, gastric, and colorectal neoplastic lesions. To develop common worldwide terminology for gastrointestinal epithelial neoplasia. Thirty one pathologists from 12 countries reviewed 35 gastric, 20 colorectal, and 21 oesophageal biopsy and resection specimens. The extent of diagnostic agreement between those with Western and Japanese viewpoints was assessed by kappa statistics. The pathologists met in Vienna to discuss the results and to develop a new consensus terminology. The large differences between the conventional Western and Japanese diagnoses were confirmed (percentage of specimens for which there was agreement and kappa values: 37% and 0.16 for gastric; 45% and 0.27 for colorectal; and 14% and 0.01 for oesophageal lesions). There was much better agreement among pathologists (71% and 0.55 for gastric; 65% and 0.47 for colorectal; and 62% and 0.31 for oesophageal lesions) when the original assessments of the specimens were regrouped into the categories of the proposed Vienna classification of gastrointestinal epithelial neoplasia: (1) negative for neoplasia/dysplasia, (2) indefinite for neoplasia/dysplasia, (3) non-invasive low grade neoplasia (low grade adenoma/dysplasia), (4) non-invasive high grade neoplasia (high grade adenoma/dysplasia, non-invasive carcinoma and suspicion of invasive carcinoma), and (5) invasive neoplasia (intramucosal carcinoma, submucosal carcinoma or beyond). The differences between Western and Japanese pathologists in the diagnostic classification of gastrointestinal epithelial neoplastic lesions can be resolved largely by adopting the proposed terminology, which is based on cytological and architectural severity and invasion status.