Efficacy of deeper tissue sections for colorectal serrated polyps histologically diagnosed as normal mucosa.

BACKGROUND AND STUDY AIMS: Discrepancies between endoscopic and histological diagnoses occasionally occur after colorectal polypectomy. This study aimed to evaluate the diagnostic impact of additional histological sections on serrated polyps.

PATIENTS AND

METHODS

We conducted a retrospective cross-sectional study of resected colorectal polyps between June 2023 and August 2023. Polyps that were endoscopically suspected to be sessile serrated lesions (SSLs) or hyperplastic polyps and resected en bloc were included. Lesions initially diagnosed as normal mucosa were subjected to deeper sectioning and histopathological re-evaluation. Clinicopathological and endoscopic features, including endoscopic SSL diagnosis score, were analysed.

RESULTS

Among the 276 eligible lesions, 117 were initially diagnosed as normal mucosa. Deeper sectioning corrected the histopathological diagnosis in 50% of these cases, identifying 5 SSLs and 53 hyperplastic polyps. The lesions reclassified in deeper sections were significantly smaller than those diagnosed in the first sections (P < 0.001). Compared with the "normal mucosa by first and deeper sections" group, the "SSL by deeper section" group showed significantly higher SSL diagnosis scores, including features such as larger size, mucus cap, and indistinct borders (P < 0.01).

CONCLUSIONS

Additional histological sectioning significantly improved the diagnostic yield for serrated polyps initially diagnosed as normal mucosa, particularly in small lesions. This effect was most evident in lesions that were ultimately classified as hyperplastic polyps. Endoscopic features suggestive of SSLs were also associated with upgraded diagnoses, although the number of SSL cases was limited.