Is it possible to define a better ASCUS class in cervicovaginal screening? A review of 187 cases.

OBJECTIVE: To try to better define the cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS) in a cervical screening protocol. STUDY DESIGN: Smears from 187 patients with cytologic diagnoses of ASCUS and histologic or two years' cytologic/colposcopic follow-up were reviewed. When an ASCUS diagnosis was confirmed, it was done strictly on the basis of the morphologic criteria recommended by the Regione Emilia Romagna Screening Protocol in 1997, trying also to subclassify ASCUS into favor reactive or favor neoplasia. RESULTS: Seventy ASCUS cases were negative (37.4%). Three cases (1.6%) were low grade squamous intraepithelial lesion, and seven (3.8%) were high grade squamous intraepithelial lesion. One hundred seven ASCUS cases (57.2%) were confirmed. Among the 70 negative cases, 36 (51.4%) had reactive changes on biopsy, 30 (42.9%) koilocytosis, 3 cervical intraepithelial neoplasia (CIN 1) and one CIN not otherwise specified (5.7% total). CONCLUSION: Reclassification of ASCUS cases using tighter criteria reduced them to a rate of 57.2% but missed 30 patients with histologic diagnoses of koilocytosis and 4 with histologic diagnoses of CIN.

Intralaboratory reproducibility of cervical cytology diagnoses in the external quality assurance scheme of the Emilia-Romagna region of Italy.

In an external quality assurance (EQA) scheme, 110 selected cervical smears were independently reported by seven cytology laboratories using the 1988 Bethesda System. In one of these, a random sample of 60 study smears was independently classified by five cytologists before undergoing joint examination according to EQA protocol. Internal agreement (i.e., among these cytologists) was compared with external agreement (between these cytologists and the other six laboratories) and with interlaboratory agreement (among these laboratories). The kappa value for internal agreement on sample adequacy (0.57) was considerably greater than those for external (0.16) and interlaboratory agreement (0.10). For interpretation of epithelial abnormalities, internal kappa was excellent (0.80) but not substantially greater compared with external kappa (0.66) and interlaboratory kappa (0.70). Calculation of class-specific kappa values revealed (a) that superiority of internal agreement on sample adequacy was restricted to the notations of "less than optimal" and of "satisfactory," and (b) that internal increase in agreement on cytologic abnormalities was substantial for the diagnosis of "atypical cells of undetermined significance."