title: The Vienna classification applied to colorectal adenomas.
abstract: OBJECTIVE
  In 1999, a group of Western and Asian pathologists gathered in Vienna reached consensus regarding the classification of gastrointestinal epithelial neoplasia. In this study, that classification is applied to colorectal adenomas.
  
  
  METHODS
  Colorectal adenomas from 1552 patients were histologically classified according to the categories listed in Vienna: category 3, low-grade dysplasia; 4.1, high-grade dysplasia; 4.2, carcinoma in situ; 4.3, suspicious of intramucosal carcinoma; 5.1, intramucosal carcinoma; and 5.2, submucosal carcinoma. The criteria used to diagnose these lesions are described in detail. Adenomas with dysplasia (categories 3 and 4.1) or with carcinoma (categories 4.2, 4.3, 5.1 and 5.2) were analyzed separately. On basis of their configuration, adenomas were classified into tubular, tubulovillous, villous, serrated, microtubular and combined phenotypes (i.e. other than tubulovillous).
  
  
  RESULTS
  The highest percentage of adenomas with carcinoma was found amongst villous adenomas (29.6%), followed by combined adenomas (27.8%). Villous adenoma with carcinoma was the most frequent neoplasia at all ages; combined adenomas with carcinoma were more frequent among younger patients. In elderly patients (> or = 60 years of age) the highest percentage of adenomas with carcinoma was recorded in villous adenomas (28.1%), followed by serrated adenomas (19.2%). Villous adenomas and combined adenomas with carcinoma were more frequent in males.
  
  
  CONCLUSIONS
  The Vienna classification of colorectal adenomas seems to be influenced by parameters inherent to the patient such as age and sex and by the histological phenotype of the adenoma. With the recent improvement in medical technology it is possible to laser-microdissect a defined group of neoplastic glands (such as with carcinoma in situ or with intramucosal carcinoma) for specific molecular analysis. This modern technology will permit in future the translation of histological structures into molecular terms.
authors.affiliation: Department of Pathology and Oncology, University of Florence, Florence, Italy. carlos.rubio@onkpat.ki.se
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Rubio
authors.forename: Gabriella
authors.initials: G
authors.lastname: Nesi
authors.forename: Lucca
authors.initials: L
authors.lastname: Messerini
authors.forename: Gian Carlo
authors.initials: GC
authors.lastname: Zampi
authors.forename: Koichi
authors.initials: K
authors.lastname: Mandai
authors.forename: Masayuki
authors.initials: M
authors.lastname: Itabashi
authors.forename: Kaiyo
authors.initials: K
authors.lastname: Takubo
mesh_terms: D000236:Adenoma / Q000145:classification*; D001317:Austria; D015179:Colorectal Neoplasms / Q000145:classification*; D003245:Consensus Statements as Topic; D005260:Female; D006801:Humans; D008297:Male; D018709:Statistics, Nonparametric; D009626:Terminology as Topic