title: p16(INK4a) and ProEx C immunostains facilitate differential diagnosis of hyperchromatic crowded groups in liquid-based Papanicolaou tests with menstrual contamination.
abstract: OBJECTIVE
  Evaluation of hyperchromatic crowded groups in Papanicolaou (Pap) tests from women during menstruation can be a diagnostic pitfall due to similar morphological appearances with significant cervical lesions. We studied the results of p16(INK4a) and ProEx C on cell blocks from Pap tests during menstruation in an attempt to facilitate the differentiation.
  
  
  METHODS
  Immunohistochemical stains for p16(INK4a) and ProEx C were performed on 25 cell blocks prepared from residual liquid-based cervical material with menstrual contamination.
  
  
  RESULTS
  Strong, diffuse, and full thickness staining pattern for p16(INK4a) and ProEx C was observed in cases of high-grade squamous intraepithelial lesion (HSIL) and small cell carcinoma of the cervix. The low-grade squamous intraepithelial lesion cases and cases negative for intraepithelial lesion or malignancy were negative for ProEx C, with focal staining for p16(INK4a). The benign endometrial cells had either negative or focal patchy staining, which is often associated with tubal metaplasia.
  
  
  CONCLUSIONS
  p16(INK4a) and ProEx C are sensitive markers for identifying significant lesions in Pap test specimens with menstrual contamination. Patchy/mosaic staining may be seen in benign endometrial tissue with tubal metaplasia, but strong, diffuse staining likely indicates HSIL or carcinoma. These findings can be helpful in interpreting hyperchromatic crowded groups in menstrual Pap specimens. Further study may be prudent, being aware of the small study group.
authors.affiliation: Department of Pathology and Genomic Medicine, The Methodist Hospital, Houston, TX 77030, USA. yge@tmhs.org
authors.forename: Yimin
authors.initials: Y
authors.lastname: Ge
authors.forename: Dina R
authors.initials: DR
authors.lastname: Mody
authors.forename: Debora
authors.initials: D
authors.lastname: Smith
authors.forename: Rose
authors.initials: R
authors.lastname: Anton
mesh_terms: D000328:Adult; D016477:Artifacts; D014408:Biomarkers, Tumor / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008598:Menstruation / Q000097:blood*; D008875:Middle Aged; D064111:Minichromosome Maintenance Complex Component 2; D009687:Nuclear Proteins / Q000378:metabolism*; D065006:Papanicolaou Test; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D014626:Vaginal Smears; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D009687:Nuclear Proteins; C084859:MCM2 protein, human; D064111:Minichromosome Maintenance Complex Component 2