title: Increased sensitivity of anal cytology in evaluation of internal compared with external lesions.
abstract: OBJECTIVE
  To investigate the impact of keratin on the accuracy of internal and external anal brush sampling of known lesions.
  
  
  METHODS
  A group of 46 human immunodeficiency virus (HIV)-seropositive patients underwent external and internal anal brush sampling before biopsy of known lesions. RESULTS; A total of 92 ThinPrep (46 external, 46 internal) an 211 biopsies were examined. The sensitivity and specificity for internal lesions positive and negative for anal squa mous intraepithelial lesion (ASIL) was 91.1% and 42.8%, respectively; and for external lesions was 79.4% and 100%, respectively. Low cellularity on cytology and markedly thickened keratin on biopsy were significantly more common in external compared with internal lesions (p < 0.0001).
  
  
  CONCLUSIONS
  We conclude that hyperkeratosis interferes with adequate sampling and accurate grading of external anal lesions by brush sampling.
authors: Department of Pathology, Graduate Hospital, Drexel University School of Medicine, Philadelphia, Pennsylvania, USA. fg24@drexel.edu
authors: Fernando U
authors: FU
authors: Garcia
authors: Marian M
authors: MM
authors: Haber
authors: Jeffrey
authors: J
authors: Butcher
authors: Meenu
authors: M
authors: Sharma
authors: Deborah
authors: D
authors: Nagle
mesh_terms: D000293:Adolescent; D000328:Adult; D001003:Anal Canal / Q000473:pathology*; D001005:Anus Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D002278:Carcinoma in Situ / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D003581:Cytodiagnosis / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006679:HIV Seropositivity / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007633:Keratins / Q000378:metabolism; D007642:Keratosis / Q000150:complications / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results
chemical_list: D007633:Keratins