Objective: To investigate how the histopathological picture of endoscopic biopsy specimens related to that of transmural sections and also how these related to the endoscopic findings.
Design: Prospective controlled study.
Patients and methods: Intraoperative endoscopy was performed on 19 patients with Crohn's disease and mucosal biopsies were obtained from various bowel segments that were to be resected. The histopathological appearance of mucosal biopsies was compared to that of transmural bowel sections and to endoscopic findings. Ten patients undergoing surgery for colonic cancer were used as controls.
Results: Poor agreement was found between the pathologist's assessment of biopsy specimens and transmural bowel sections (kappa < 0.38) for all histological variables. The endoscopic assessment of inflammatory severity had a better correlation with global histological assessment of transmural bowel wall sections (r = 0.75) than with a global histological assessment of endoscopic biopsy specimens (r = 0.65).
Conclusion: Endoscopic assessment of inflammation in Crohn's disease better reflects transmural histopathology than mucosal biopsy and thus the severity and extent of inflammation. Routine biopsy sampling is of limited value in Crohn's disease.