Résumé
Introduction: Diagnosis of inflammatory bowel disease (IBD) and other inflammatory conditions of the colon cannot beestablished when only one or few features are present as they share many pathological features. Hence, this study is undertakento develop reproducible criteria which are valid in the diagnosis of IBD and to differentiate it further from ulcerative colitis (UC)and Crohn’s disease (CD).Purpose: The purpose of the study was (1) to study the histopathological patterns of the colonic biopsy specimen, (2) to developthe reproducible criteria which aid in the diagnosis of UC and CD, and (3) to evaluate the extent of interobserver variabilityover the final diagnosis.Materials and Methods: Endoscopic punch biopsy procedure was done for 35 cases with suspected IBD which were sent tothe Histopathology Department of Bengaluru Medical College. Tissue bits were fixed in 10% formalin and processed by theconventional method and embedded in paraffin blocks. Sections from these blocks were stained with hematoxylin and eosinaccording to standard procedures. After initial histomorphological reporting was done, the 35 slides were reported again by twopathologists. Cases with proven malignancy were excluded from the study.Results: UC was diagnosed in 19 cases (53%) of 35 cases followed by indefinite for IBD in nine cases (25%). CD was seenin five cases (14%) followed by tuberculosis in two cases (5%). One case had evidence of dysplasia along with features ofUC. The agreement between pathologists for the final diagnosis is 68.5%. Based on P value, the significant features whichare most useful in the diagnosis of UC are: For activity – (1) cryptitis, (2) neutrophilic infiltration in lamina propria, and (3) cryptabscess; for chronicity – (1) crypt distortion, (2) crypt branching, (3) Mucin depletion, (4) crypt atrophy, and (5) crypt dilation.Conclusion: UC was found to be more commonly reported among the IBD cases. Considerable disagreement can be seenbetween experienced pathologists reporting the same slides. Therefore, salient histological features based on better reproducibilityalong with adequate clinical and endoscopy findings can aid in distinguishing between UC and CD.