Rescreening of atypical cervicovaginal smears using PAPNET

BACKGROUND, Atypical squamous cells of undetermined significance (ASCUS) is a cytopathologic term used to describe cases without specific pathologic s ubstratum. Between 10-60% of ASCUS cases correspond to squamous intraepithe lial lesions (SIL). METHODS, The objectives of this study were: 1) to detect the pathologic sig nificance of ASCUS in study patients, 2) to determine whether PAPNET identi fies these cases, and 3) to compare the results of PAPNET with those of a s econd conventional screening. One hundred and sixty-three consecutive patie nts with the cytologic diagnosis of ASCUS and adequate follow-up were selec ted. Of these, 111 patients had colposcopic lesions and biopsies were perfo rmed; in the remaining 52 cases colposcopy was negative, as were 3 consecut ive annual Papanicolaou smears. In a blind review, all 163 cases were rescr eened using PAPNET. A second manual screening was performed for comparison. RESULTS. One hundred and twenty-six of the 163 cases (77.3%) showed no SIL on biopsy or follow-up. Of the 37 pathologic cases, the diagnosis was koilo cytosis (flat condyloma) in 13 cases (8%), cervical intraepithelial neoplas ia (CIN) type I in 11 cases (6.8%) low grade SIL [LSIL] in a total of 24 ca ses [14.8%]), and CIN II-III or high grade SIL (HSIL) in 11 cases (6.8%). I n the review using PAPNET, 57 previous ASCUS cases were classified correctl y as negative, and 7 of 13 koilocytosis cases (54%), 9 of 11 CIN I cases (8 2%), and 7 of 11 CIN II-III cases (64%) were diagnosed correctly. In the se cond conventional screening, 74 cases were negative and;7 cases were ASCUS; only 3 of 13 koilocytosis cases (23%), 4 of 11 CIN I cases (36.4%) and 5 o f 11 CIN II-III cases (45.5%) were reclassified correctly. CONCLUSIONS. Among 163 patients with ASCUS, 77.3% had no precancerous squam ous lesions. Concordance with definitive diagnosis was more accurate in our study using PAPNET analysis (Kappa index [K] = 0.7158) than by second conv entional screening (K = 0.4537). Furthermore, we reclassified 35% of smears as negative and 15% as SIL. Cancer (Cancer Cytopathol 1998;84:361-5. (C) 1 998 American Cancer Society.