BACKGROUND: There are lesions that are still being missed in colonoscopy. Many of those could be superficially elevated serrated lesions or depressed ones. AIMS: The aim of this study was to compare the histopathological characteristics of these lesions and their risks for submucosal carcinoma. METHODS: This is a retrospective, cross-sectional, and observational study comparing 217 superficially elevated serrated lesions larger than 5 mm resected by colonoscopies (G1) with 558 depressed lesions (G2). RESULTS: In G1, 217 lesions were found in 12,653 (1.7%) colonoscopies; in G2, 558 lesions were found in 36,174 (1.5%) colonoscopies. In G1, 63.4% were women and in G2, there was no gender predominance. The average size of G1 was 16.2 mm and G2 was 9.2 mm (p<0.001). G1 predominated on the proximal colon and G2 on the distal and rectum (p<0.001). In G1, there were 214 (98.6%) low-grade intramucosal neoplasia and 3 (1.4%) high-grade intramucosal neoplasia. Excluding 126 hyperplastic polyps and considering 91 sessile serrated adenomas in G1, we observed 88 (96.7%) low-grade intramucosal neoplasia and 3 (3.3%) high-grade intramucosal neoplasia; in G2, we observed 417 (74.7%) low-grade intramucosal neoplasia, 113 (20.3%) high-grade intramucosal neoplasia, and 28 (5.0%) submucosal adenocarcinomas (p<0.001). CONCLUSION: Depressed lesions significantly had more high-grade intramucosal neoplasia and more invasive carcinomas in the submucosal layer than superficially elevated serrated lesions and more than superficially elevated sessile serrated adenomas.

Racional: Há ainda lesões que podem ser perdidas nas colonoscopias. Muitas delas poderiam ser serrilhadas superficialmente elevadas ou deprimidas. Objetivo: Comparar as características histopatológicas destas lesões e seus riscos para carcinoma invasivo para a submucosa. Método: Estudo retrospectivo, transversal, observacional comparando 217 lesões serrilhadas superficialmente elevadas com mais de 5 mm e ressecadas por colonoscopias (G1) com 558 lesões deprimidas (G2). Resultados: As 217 lesões do G1 foram encontradas em 12653 colonoscopias (1,7%) enquanto as 558 do G2 ocorreram dentre 36174 colonoscopias (1,5%). No G1, 63,4% eram mulheres e no G2 não houve predominância de gênero. O tamanho médio foi no G1, 16,2 mm e no G2, 9,2 mm (p<0,001). G1 predominaram no cólon proximal e G2, no distal e reto (p<0,001). No G1, ocorreram 214 (98,6%) neoplasias mucosas de baixo grau e três de alto grau (1,4%). Excluídos 126 pólipos hiperplásicos e considerados os 91 adenomas sésseis serrilhados, no G1 observou- se 88 (96,7%) neoplasias mucosas de baixo grau e três (3,3%) de alto grau, e no G2, 417 (74,7%) neoplasias mucosas de baixo grau 113 (20,3%) de alto grau e 28 (5,0%) adenocarcinomas invadindo a submucosa (p<0,001). Conclusões: As lesões deprimidas apresentaram significativamente mais neoplasias mucosas de alto grau e carcinomas invasivos para a submucosa do que as serrilhadas superficialmente elevadas e mais do que os adenomas sésseis serrilhados superficialmente elevados.

Objective: to compare endoscopic and histopathologic features of superficial, elevated lesions with one or more centimeters in diameter, diagnosed by videocolonoscopy on the distal and proximal colon, and subjected to mucosal resection. Methods: we conducted a retrospective, cross-sectional, observational study involving 8,075 videocolonoscopies. From this total, we evaluated 166 mucosectomies in 145 patients with superficial, elevated lesions with a diameter equal to or greater than 1cm. Results: the lesion prevalence was lower in G1 than in G2 (34.9% vs. 65%). The mean age, gender distribution and size (1.9cm in G1 versus 2.0cm in G2, p=0.921) were similar. There was no difference of mucosal surfaces in relation to the location (p=0.575). Considering Intraepithelial neoplasias, both the low grade, high grade (including carcinomas) and hyperplasic ones showedd no difference (p=0.527), nor did the neoplastic lesions when divided into serrated and non-serrated (p=0.124). Excluding 13 hyperplastic lesions and two carcinomas, 124 (82.1%) were non-serrated and 27 (17.9%), serrated. Conclusion: were found no significant differences between endoscopic and histopathological aspects of superficial, elevated lesions of 1cm or more in diameter in distal colon compared with the proximal, when resected by mucosectomy. Although not significant, there was a tendency of association between the location of the lesion and the presence of serrated features.