Retrospective Pathological Diagnosis And Clinical Analysis Of 145 Cases Of Colorectal Serrated Lesions

Objectives:Colorectal serrated lesions are histologically characterized by a saw-toothed appearance of the crypt epithelium.Insufficient understanding of the pathological and endoscopic features of colorectal serrated lesions was liable to result in missed diagnosis and misdiagnosis because of relatively lower mobidity.Clinical and pathological data of colorectal serrated lesions were analyzed retrospectively in order to improve the recognition of this kind of lesionsMethods:145 cases of colorectal serrated adenomas(SA)were recruited in our study,which were primarily diagnosed in Department of pathology of Wuxi people's Hospital affiliated to Nanjing Medical University between January 2008 and May 2016.All the SAs were reassessed by two experienced pathologists according to WHO diagnostic criteria in 2010 and the United States expert consensus of colorectal serrated lesions in 2012.The clinical,endoscopic and pathological data of serrated lesions were collected and analyzed concurrently.Results:11 cases of sessile serrated adenomas(SSA),46 cases of traditional serrated adenomas(TSA)and 88 cases of hyperplastic polyps(HP)were diagnosed after the reassessment of 145 cases of colorectal serrated adenoma by two experienced pathologists.Of these 145 lesions,28 lesions were localized in the proximal colon and 117 lesions in the distal colon.On the development morphological classification,62 lesions were protruding type and 83 lesions were flat type.The mean diameter of 145 lesions was 7.77±4.29mm.In all 57 cases of colorectal serrated adenomas,there were 51 cases with low-grade intraepithelial neoplasia,2 cases with high-grade intraepithelial neoplasia and 4 cases without displasia.25 cases of colorectal serrated adenomas were low-risk adenomas and 32 cases were high-risk adenomas.The hyperplastic polyps were often<10mm in diameter,with a flat appearance and mainly located in the distal colon.Compared with the hyperplastic polyps,the colorectal serrated adenomas in our study were commonly found in the distal colon but often?10mm in diameter with a protruding appearance.The patients with the colorectal serrated adenoma had a higher proportion of smoking history than patients with hyperplastic polyp.In contrast to the cases of HP,comorbidity with traditional adenoma or adenocarcinoma was more often found in the cases of SA.SSA was more commonly located in the proximal colon and presented with a flat appearance.TSA was mainly located in the distal colon and with a protruding appearance.There were no statistically significant differences in gender,age,size of the lesion,the grade of adenoma risk,and the grade of intraepithelial neoplasia between SSA and TSA.Conclusions:1.Differential diagnosis of the subtypes of colorectal serrated lesion is difficult because of the histological similarity to some degree among these variants.Pathologists should improve diagnostic accuracy of colorectal serrated lesions by continuous learning.2.Differences in clinical and endoscopic characteristics among the subtypes of colorectal serrated lesion are helpful in the diagnosis of the colorectal serrated lesions by endoscopic physicians and pathologists.