The purpose of this study is to evaluate the histologic correlations and the clinical significance among patients with atypical squamous cells of undetermined significance (ASCUS), atypical glandular cells of undetermined significance(AGUS) and benign endometrial cells identified on cervical Pap smear screening.

The computerized files of the Department of Pathology at Samsung Cheil Hospital were searched from 1991 to 1997 to evaluate the annual statistics of cytologic diagnoses including normal/benign, ASCUS, AGUS, low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion(HSIL) and cancer classified by the Bethesda System(TBS). Cytohistologic correlations on follow-up were separately analysed in ASCUS(190 cases), AGUS(268 cases) and benign endometrial cells(169 cases), respectively. Additionally, post-menopausal squamous atypia(83 cases) were also included in this study. TBS terminology was used in both cytologic and histologic diagnoses.

During 7-year period (1991-1997), 447,049 cervicovaginal smears were evaluated. The median rate of abnormal cytology was 4.4%, with 2.1% of ASCUS, 2.06% of squamous intraepithelial lesion(SIL), and 0.08% of AGUS. The median ratio of ASCUS versus SIL was 1.24. Specimen adequacy was evaluated on 47,525 cases, of which categories of "satisfactory for evaluation but limited by" and "unsatisfactory for evaluation" were 28.3% and 0.03%, res-pectively. Follow-up of 190 patients with ASCUS cytology showed 30%(57 cases) with SIL on biopsy; 18%(35cases) with LSIL, 11%(21cases) with HSIL, and 1%(1case) with microinvasive squamous cell carcinoma. On histologic examination, 77%(37/48cases) with ASCUS favoring SIL revealed SIL in contrast to 14%(20/142cases) with ASCUS favoring reactive change, which is statistically significant.(Chi-Square test, P<0.0001). Of 83 cases of post-menopausal squamous atypia(PSA), smears with LSIL showed 34.9%(15/43cases) with LSIL on biopsy. 268 patients with AGUS smears had 25%(67cases) with clinically significant cervical or endometrial lesions on histologic examinations. Among 17.9%(48cases) with cervical lesions, squamous abnormalities were 10.5%(28cases); including 1.5%(4cases) with LSIL and 9.0%(24cases) with HSIL. Glandular lesions in cervix were 7.5%(20cases); 3.0%(8cases) of glandular atypia or dysplasia, 1.9%(5cases of adenocarcinoma in situ, 1.1%(3cases) of microinvasive adenocarcinoma and 1.5%(4cases) of adenocarcinoma. Of 7.1%(19cases) of endometrial lesions, 2.2%(6cases) was endometrial hy-perplasia, 4.1%(11cases) endometrial carcinoma, 0.4%(1case) MMMT and 0.4%(1case) metastatic adenocarcinoma from stomach were verified. The pathologies of 169 cases with benign endometrial cells shed in cervicovaginal smears were confirmed to be endometrial polyp(8.3%), endometrial hyperplasia(4.1%) and endometrial carcinoma(5.9%).

The results of this study indicates that clinicians should communicate with pathologists for proper management of abnormal cytology. Further evaluation and decision of management should be made based on input from pathologists as well as on clinical setting and professional guidelines.