title: The significance of ectopic crypt formation in the differential diagnosis of colorectal polyps.
abstract: BACKGROUND
  Ectopic crypts, defined as abnormally positioned crypts that have lost their orientation toward the muscularis mucosae, have been suggested to be the best defining histologic feature of traditional serrated adenoma (TSA). However, the significance of ectopic crypt formation (ECF) in the distinction between TSA and conventional adenoma (CA) has rarely been studied.
  
  
  METHODS
  We designed this study to determine if ECF can be found in CA and its presence is exclusive to TSA. We studied 107 TSAs and 191 CAs including 106 tubular adenomas (TAs), 66 tubulovillous adenomas (TVAs), and 19 villous adenomas (VAs).
  
  
  RESULTS
  ECF was identified in most (79.4%) but not all TSAs. Additionally, ECF was not infrequent in CA (62 of 191, 32.5%), and its presence correlated with the presence of a villous component and larger tumor size (each p <0.001).
  
  
  CONCLUSIONS
  Based on its strong association with the presence of a villous component and larger tumor size, ECF appears to be involved in the protuberant growth of colorectal CA. Because ECF can be found in CA, particularly in cases with a villous component, the possibility of CA should be considered before making a diagnosis of TSA when encountering colorectal polyps with ECF.
  The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_212.
authors.affiliation: Department of Pathology, Daehang hospital, 481-10 BangBae3-dong, Seoul, Seocho-gu, 137-820, Republic of Korea. mjkimdoc@gmail.com.
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Surgery, Daehang hospital, Seoul, Republic of Korea. ejlee1009@naver.com.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Poongnap 2-Dong, Seoul, Songpa-Gu, 138-736, Republic of Korea. als1000@hanmail.net.
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Chun
authors.affiliation: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Poongnap 2-Dong, Seoul, Songpa-Gu, 138-736, Republic of Korea. jangsejin@amc.seoul.kr.
authors.forename: Se-Jin
authors.initials: SJ
authors.lastname: Jang
authors.affiliation: Department of Surgery, Daehang hospital, Seoul, Republic of Korea. dskim1@daehang.com.
authors.forename: Do Sun
authors.initials: DS
authors.lastname: Kim
authors.affiliation: Department of Surgery, Daehang hospital, Seoul, Republic of Korea. dhlee@daehang.com.
authors.forename: Doo Han
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Surgery, Daehang hospital, Seoul, Republic of Korea. youkgon@hanmail.net.
authors.forename: Eui Gon
authors.initials: EG
authors.lastname: Youk
mesh_terms: D058739:Aberrant Crypt Foci / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D018256:Adenomatous Polyps / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D003111:Colonic Polyps / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011237:Predictive Value of Tests; D011518:Proto-Oncogene Proteins / Q000235:genetics; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D047368:Tumor Burden; D018631:ras Proteins / Q000235:genetics
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins