title: Predictive index to differentiate invasive squamous cell carcinoma from preinvasive ocular surface lesions by impression cytology.
abstract: OBJECTIVE
  In the literature, no cytological features have been identified that reliably differentiate invasive squamous cell carcinoma (SCC) from preinvasive lesions in impression cytology (IC) samples. The aim was to identify cytological features related to malignancy and apply them in a quantitative model to determine an index score with the best predictive power to differentiate SCC from preinvasive ocular surface lesions by IC.
  
  
  METHODS
  39 patients with ocular surface epithelial lesions were enrolled. IC was obtained from all lesions before surgical excision. Specimens with atypical cells were evaluated regarding 11 cytological parameters based on the 2001 Bethesda system.
  
  
  RESULTS
  Histopathological diagnosis was pterygium in one case, actinic keratosis in nine cases, intraepithelial neoplasia in nine cases and SCC in 20 cases. Analysis of the receiver operating characteristic curve revealed that a predictive index score (cut-off point) > or =4.25 presented the best relationship between sensitivity and specificity in identifying SCC (sensitivity of 95%, specificity of 93%, positive predictive value of 95% and negative predictive value of 93%).
  
  
  CONCLUSIONS
  The scoring system model presented is suitable for clinical practice in differentiating SCC from preinvasive ocular surface lesions by IC and can be better evaluated with prospective use.
authors.affiliation: Department of Ophthalmology, Federal University of São Paulo, Doctor Penaforte Mendes Street 86, São Paulo 01308-010, Brazil. jeisonbarros@hotmail.com
authors.forename: J N
authors.initials: JN
authors.lastname: Barros
authors.forename: M S
authors.initials: MS
authors.lastname: Lowen
authors.forename: P L
authors.initials: PL
authors.lastname: Ballalai
authors.forename: V L D M
authors.initials: VL
authors.lastname: Mascaro
authors.forename: J A P
authors.initials: JA
authors.lastname: Gomes
authors.forename: M C
authors.initials: MC
authors.lastname: Martins
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002278:Carcinoma in Situ / Q000175:diagnosis / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D003230:Conjunctival Neoplasms / Q000175:diagnosis / Q000473:pathology; D003316:Corneal Diseases / Q000175:diagnosis / Q000473:pathology; D003581:Cytodiagnosis / Q000379:methods; D003937:Diagnosis, Differential; D004812:Epidemiologic Methods; D005134:Eye Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D055623:Keratosis, Actinic / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D011625:Pterygium / Q000175:diagnosis / Q000473:pathology; D055815:Young Adult