부산대학교 도서관

Aims Traditional serrated adenomas ( TSAs) account for 5% of serrated polyps, and have a villiform architecture, eosinophilic cells with a brush border, and indented, flat-topped luminal serrations. However, some are composed of mucin-filled goblet cells ( GCs): mucin-rich TSA (Mr TSA). The aim of this study was to determine whether this variant has unique features as compared with classic TSA ( cTSA). Methods and results One hundred and fifty-six TSAs were retrieved from the period 2010-2016. Patient demographics, site of polyps and 16 microscopic variables were evaluated. TSAs containing ≥50% GCs were classified as Mr TSAs. Ectopic crypt foci ( ECFs) were quantified as low (1-10) or high (>10), counted at ×200 magnification, and the average was taken for 10 fields. Twenty-four fulfilled the criteria for Mr TSA. In males, Mr TSAs (65%) were more prevalent than cTSAs (55%). There was no age difference, and both variants had a predilection for the left colon, although, in the right colon, Mr TSAs were more frequent (39%) than cTSAs (10%) ( P = 0.012). Adenomatous dysplasia was present in four of 24 Mr TSAs (low grade, 3; high grade, 1). The most distinctive features of Mr TSAs were: a variable growth pattern [endophytic (9%), mixed (30%), or villiform/exophytic (61%)], and a lower frequency of ECFs ( P = 0.001) and more intraepithelial lymphocytes ( P < 0.05) than in cTSAs. Mr TSAs retain characteristic luminal serrations, at least focally. Inflamed Mr TSAs can mimic inflammatory polyps and hamartomatous polyps (when there are >95% GCs). Conclusions Mr TSA is characterized by >50% GCs, and fewer ECFs than cTSA, but with preservation of archetypal luminal serrations. Awareness of this variant will prevent misdiagnosis, given the association of TSA with the accelerated pathway to colorectal cancer. [ABSTRACT FROM AUTHOR]