title: Clinicopathological and immunohistological features of polypoid endometriosis.
abstract: OBJECTIVE
  To compare clinicopathological and immunohistochemical features of polypoid endometriosis (PE) and non-polypoid endometriosis (NPE).
  
  
  RESULTS
  Fifteen cases of PE and 20 cases of NPE were assessed. All cases were stained immunohistochemically for CD10 and p16 and the proportion of p16-positive stromal and epithelial cells was estimated. On review, 10 PE cases resembled NPE histologically but occurred at mucosal or serosal surfaces, or within cyst cavities, that permitted polyp formation. These cases had a similar age distribution and immunohistochemical profile to NPE. The remaining five PE cases showed histological similarity to eutopic endometrial polyps; these occurred in older patients, and showed significantly greater stromal and epithelial p16 immunoreactivity.
  
  
  CONCLUSIONS
  There are two main subgroups of PE. The majority of cases in this series showed similar histological features to NPE, but involved anatomical sites that facilitated exophytic or polypoid growth. The remaining PE cases resembled eutopic endometrial polyps histologically and immunophenotypically and they occurred in older patients. These findings suggest that such lesions are 'true' polyps sharing a pathogenetic relationship with similar lesions arising in the endometrium.
authors.affiliation: Department of Pathology, King Edward Memorial Hospital, Perth, WA, Australia.|School of Women's and Infants' Health, University of Western Australia, Perth, WA, Australia.
authors.forename: Colin J R
authors.initials: CJ
authors.lastname: Stewart
authors.affiliation: Centre for Applied Statistics, University of Western Australia, Perth, WA, Australia.|Department of Research, Sir Charles Gairdner Hospital, Perth, WA, Australia.
authors.forename: Chrianna
authors.initials: C
authors.lastname: Bharat
mesh_terms: D000328:Adult; D000368:Aged; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D004715:Endometriosis / Q000378:metabolism / Q000473:pathology*; D004717:Endometrium / Q000378:metabolism / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D015260:Neprilysin / Q000378:metabolism; D011127:Polyps / Q000378:metabolism / Q000473:pathology*; D055815:Young Adult
chemical_list: C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D015260:Neprilysin
keywords: endometrial polyp; endometriosis; immunohistochemistry; p16; polypoid