LAUSR

Background: Colonic crypts with normal epithelial lining exhibiting corrupted shapes (NECS) have been previously found beneath the adenomatous tissue of polypoid conventional adenomas, in both rats and humans. Aim: To assess the frequency of NECS in non-polypoid colonic flat adenomas (FAs) and lateral-spreading adenomas (LSAs). Materials and Methods: Histological hematoxylin and eosin-stained sections from 51 non-polypoid colonic adenomas were scrutinized over a 10-mm field of vision (FOV). FAs were regarded lesions encompassed within the FOV and LSAs as those surpassing that limit. The NECS/mm ratio was calculated in individual lesions as the number of NECS beneath the adenomatous tissue, divided by the length (mm) of the FA and LSA. Results: Out of the 51 non-polypoid adenomas, 27 were FAs and the remaining 24 LSAs. All 51 non-polypoid lesions were tubular adenomas. The mean number of NECS in FAs was 6.29 (range=2-10) and in LSAs was 15.29 (range=7-41) (p<0.05). On the other hand, the mean NECS/mm ratio in FAs was 0.94 (range=0.50-2.00) and in LSAs was 0.92 (range=0.40-2.93). Thus, no essential differences in the number of NECS/mm was found between FA and LSA. Conclusion: The accretion of NECS below the neoplastic canopy of FA and LSA contrasts with the rare occurrence of NECS in normal colonic mucosa. This finding emerges as a previously unaddressed major event, an event that might play an important role in the histogenesis of non-polypoid adenomas of the colon.