title: Atypical squamous cells of undetermined significance on cervical smears: follow-up study of an Asian screening population.
abstract: BACKGROUND
  The current study reports on the significance of cervical smears identified as atypical squamous cells of undetermined significance (ASCUS) in the largest Asian screening population to date.
  
  
  METHODS
  From January 1998 to December 1999, 190,000 cervical smears were evaluated by the cervical cytology laboratory at the University of Hong Kong (Hong Kong, China). From these smears, 5579 ASCUS were identified. Follow-up cytology and histology findings were analyzed.
  
  
  RESULTS
  Follow-up cytology or biopsy results were retrieved for 3601 women (64.5%). Of these, 544 (9.8%) and 96 women (1.7%) were found to have low-grade (LSIL) and high-grade (HSIL) squamous intraepithelial lesions, respectively. Biopsy results were obtained for 198 (36.4%) of the 544 women with LSIL. One hundred seventy-nine (32.9%) and 19 women (3.5%) were confirmed to have cervical intraepithelial neoplasia (CIN)-1 and CIN-2-CIN-3, respectively. Biopsy results were retrieved for 53 (55.2%) women with HSIL. Forty patients (41.7%) were confirmed to have CIN-2-CIN-3, whereas CIN-1 was found in the remaining patients. One woman with squamous cell carcinoma was diagnosed by colposcopic biopsy after immediate referral following a diagnosis of ASCUS. There was a significantly larger proportion of LSIL or HSIL (P < 0.0001) or higher-grade findings in women with ASCUS compared with the general screening population. Infective organisms were identified in 412 women (7.4%) with ASCUS. These women had a decreased risk of subsequent development of LSIL (P < 0.0001) or HSIL (P = 0.027).
  
  
  CONCLUSIONS
  ASCUS smears indicated an increased risk of HSIL or carcinoma. The authors suggested careful patient follow-up in such cases.
authors.affiliation: Department of Pathology, The University of Hong Kong, Hong Kong, China. anycheun@hkucc.hku.hk
authors.forename: Annie N Y
authors.initials: AN
authors.lastname: Cheung
authors.forename: Elaine F
authors.initials: EF
authors.lastname: Szeto
authors.forename: Kin-Man
authors.initials: KM
authors.lastname: Ng
authors.forename: Ka-Wah
authors.initials: KW
authors.lastname: Fong
authors.forename: Ang Chan Elvinia
authors.initials: AC
authors.lastname: Yeung
authors.forename: Obe K L
authors.initials: OK
authors.lastname: Tsun
authors.forename: Ui-Soon
authors.initials: US
authors.lastname: Khoo
authors.forename: Kelvin Y K
authors.initials: KY
authors.lastname: Chan
authors.forename: Anita W Y
authors.initials: AW
authors.lastname: Ng
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001706:Biopsy; D005260:Female; D005500:Follow-Up Studies; D006723:Hong Kong; D006801:Humans; D008403:Mass Screening; D008875:Middle Aged; D012306:Risk; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis