Atypical Squamous Cells-Cannot Exclude High-Grade Squamous Intraepithelial Lesion (ASC-H): A Result Not to Be Ignored

Objective: The objective of this study was to determine the risk of a clinically significant lesion associated with the diagnosis of atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (ASC-H) on cervical cytology (Pap smear). Methods: This was a retrospective; observational; descriptive study. A computerized database containing cytologic and histologic information for the health region was used to identify women with a diagnosis of ASC-H on a Pap smear performed between January 1 and December 31, 2002. All pertinent pathology data (cytopathology, histopathology, and surgical specimens) were examined. Patients were excluded if they had a diagnosis of cervical cancer; adenocarcinoma in situ (AIS), or high-grade squamous intraepithelial lesion (HSIL) prior to the index Pap smear. Results: During the study period, 727 of 241 841 Pap smears (0.3%) were reported as ASC-H in 655 patients. Ninety-one patients had a previous diagnosis of cervical cancer, AIS, or HSIL and were excluded from analysis, and 12 patients on review did not have ASC-H. There were no follow-up data for 35 of the remaining 552 patients, leaving 517 patients in the study group. In this group, the rates of histologically proven cervical lesions were 2.9% (15/517) for cervical cancer, 1.7% (9/517) for AIS, and 65.6% (339/517) for HSIL. Women undergoing a procedure that included histological examination were more likely to have a significant lesion discovered. Conclusion: The diagnosis of ASC-H on Pap smear is associated with an appreciable risk of clinically significant disease. Patients with an ASC-H Pap smear result should undergo timely colposcopic and histologic assessment to rule out HSIL, AIS, and cervical cancer.