Diagnostic Yield of Dysplasia in Polyp-adjacent Biopsies for Patients with Inflammatory Bowel Disease: A Cross-sectional Study.

Introduction: Patients with inflammatory bowel disease (IBD) undergoing polypectomy are recommended by current guidelines to have biopsies taken from adjacent mucosa to determine whether there is dysplasia present. With improvements in endoscopic imaging, it is now possible to characterize colonic lesions with higher levels of confidence than previously. We have reviewed the diagnostic yield of polyp-adjacent biopsies in IBD. Materials and Methods: A systematic search of our histopathology database revealed cases in which polyps had been endoscopically resected or biopsied in patients with IBD. Endoscopy reports and medical records were reviewed, and patient demographic and disease-specific details were recorded, along with details of polyp characteristics and histopathology outcomes. Results: Three hundred and two polyps were biopsied or resected in 131 patients undergoing 178 colonoscopies. The median polyp size was 4 mm (range 1-45), and the predominant morphology was Paris 0-Is (n = 98, 32%). The histology was tubular adenoma in 76 (25%), tubulovillous adenoma in 14 (5%), hyperplastic in 112 (37%), post-inflammatory in 32 (11%), sessile serrated polyp in 31 (10%), traditional serrated adenoma in 2 (0.7%), flat high-grade dysplasia or cancer in 2 (0.7%) and other in 33 (11%). Dysplasia in adjacent biopsies was detected in 2 patients (0.7%), and was endoscopically visible in both cases. The proportion of endoscopically unsuspected dysplasia was 0/300 (0%, 95% CI 0-1.6%). Conclusion: The diagnostic yield for polyp-adjacent biopsies in patients with IBD is negligible. With high-definition technology and chromoendoscopy, it may no longer be necessary to biopsy endoscopically normal adjacent tissue to detect invisible dysplasia.