ABSTRACT
Objective: To assess the histologic correlates of atypical squamous cells of undetermined significance (ASCUS) Pap smear and analyze its impact on the accuracy of Pap smear. Study design: A total of 7,546 women were screened for early detection of cervical cancer. The women with ASCUS diagnosis were further qualified as ASCUS favor reactive, ASCUS favor LSIL (low grade squamous intraepithelial lesion) and ASC-H (cannot exclude HSIL) according to the Bethesda 1991 system and the Bethesda 2001 system of reporting. ASCUS favor reactive were followed up by a repeat smear examination and persistent ASCUS cases were taken up for colposcopy and biopsy if indicated. All ASCUS favor LSIL and ASC-H cases were taken up for immediate colposcopy. Results: On cytohistologic correlation of diagnosed ASCUS cases, the total 80 ASCUS favor reactive cases, 37 showed chronic cervicitis with or without squamous metaplasia, the accuracy 50.41%. The total 24 ASCUS favor LSIL, 8 showed HPV (human papilloma virus) infection/ CIN 1 (cervical intraepithelial neoplasia)/ CIN1+HPV infection, the accuracy 77.24%. The total 19 ASC-H, 5 showed CIN2 / CIN3 / CIN2, CIN3 + HPV infection, the accuracy 85.36%. Conclusion: Our data showed a good accuracy in ASC-H group. ASCUS is a problem to define, diagnose, reproduce and manage. The diagnosis of ASCUS is wide, ranging from a totally chronic cervicitis, HPV infection and CIN. Careful attention to subtle cytomorphologic characteristics may be helpful for a more definitive subdivision of ASCUS terminology into ASC-US and ASC-H.