Mucosal Architectural Change is an Important Feature in Distinguishing Crohn's Disease From Others in Terminal Ileum Ulcer Biopsy.

BACKGROUND: Besides Crohn's disease (CD), there are a variety of other causes that can also lead to ulcerations in the terminal ileum. The purpose of this study was to identify useful diagnostic features for CD when evaluating terminal ileum biopsies in patients with endoscopic finding of ulcers. METHODS: Five hundred and seventy-one patients with endoscopic finding of ulcers were included in this retrospective study. Five main histological features were analysed, which were crypt irregularity, mucosal thickening, villous stromal widening (including villous atrophy), granulomas, and pseudopyloric gland metaplasia. Clinical and pathological features were determined by uni- and multivariable logistic regression. Then another independent cohort of 99 patients was established for verifying this nomogram. RESULTS: The crypt irregularity, mucosal thickening, and villous stromal widening were combined to be considered as one new variable named mucosal architectural change which was an independent variable in diagnosing CD. We found that mucosal architectural change, age <40 years, the presence of granulomas, and the presence of pseudopyloric gland metaplasia were independent factors for the pathological diagnosis of CD. Then nomogram was developed, with receiver operating characteristic (ROC) curve (area under the ROC curve [AUC] = 0.927) in training sets, and ROC curve (AUC = 0.913) in validation sets. CONCLUSIONS: We found mucosal architectural change is very helpful in distinguishing CD from non-CD patients. In the context of small biopsy which may lack full scope of changes, the model developed by combining these key features is valuable in predicting a diagnosis of CD, especially in younger patients (age <40 years).