Analysis of implementing modern histological criteria for diagnosing Crohn’s disease and ulcerative colitis using biopsies

Introduction. Histological examination of intestinal biopsies is crucial for diagnosing Crohn’s disease and ulcerative colitis. This study aimed to analyze modern histological diagnostic criteria, their interpretation, and alignment with current concepts. Materials and methods. The study included 93 patients: 35 with Crohn’s disease, 58 with ulcerative colitis; 56 males, 37 females. Histological descriptions and reports were analyzed, followed by a biopsy review to clarify additional features. Results. Crypt abnormalities were detected in 77.6% of ulcerative colitis cases compared to 34.3% of Crohn’s disease cases. Villous surface changes were present in 58.6% of ulcerative colitis cases and 28.6% of Crohn’s disease cases (p=0.006). Paneth cell metaplasia was identified in five ulcerative colitis cases and one Crohn’s disease case (p=0.404). Mucin depletion occurred in 68.9% of ulcerative colitis cases, significantly more than in Crohn’s disease cases (5.7%, p<0.001). Basal plasmacytosis was noted in 75.9% of ulcerative colitis cases and 68.6% of Crohn’s disease cases. Severe, diffuse, and transmucosal cellular infiltration of the lamina propria was found in 91.4% of ulcerative colitis cases and 14.3% of Crohn’s disease cases. In contrast, focal inflammation was more frequent in Crohn’s disease (85.7%) than in ulcerative colitis (8.6%, p<0.001). Pseudopyloric metaplasia was detected in 31.4% of Crohn’s disease cases and 3.4% of ulcerative colitis cases (p<0.001). Epithelioid granulomas were found exclusively in Crohn’s disease (22.9%, p<0.001). Conclusion. The statistically significant histological parameters for diagnosing ulcerative colitis were the following: crypt branching and distortion, alterations in the mucosal surface, reduced mucus content, and diffuse inflammation. For Crohn’s disease, the significant features included focal inflammation, pseudopyloric metaplasia, and epithelioid granulomas. The final diagnosis should be based on the combination of the identified features. Keywords: ulcerative colitis, Crohn’s disease, inflammatory bowel diseases, morphological diagnosis