Abstract
Upwards of 50 million women in the United States are screened each year in order to identify the relatively few who have significant preinvasive cervical disease, grade 2 or 3 cervical intraepithelial neoplasia (CIN), or cancer. The Bethesda 2001 System distinguishes between atypical squamous cells of undetermined significance (ASC-US) and atypical squamous cells that cannot exclude a high-grade squamous intraepithelial lesion (ASC-H). Colposcopy is recommended for women having ASC-H. This retrospective study attempted to determine the cumulative risk of CIN 2 or 3 in patients with ASC-H. The study population consisted of 229 patients with ASC-H whose mean age was 33 years. Initial assessment included colposcopy, endocervical curettage, and ectocervical biopsy as indicated.At the time of initial colposcopy, 10% of women had histological evidence of CIN 2 or 3. More than 80% of lesions were identified by ectocervical biopsy. All affected women underwent electrosurgical loop excision. Of those women with normal initial findings, 134 had repeat colposcopy with liquid-based cytology after 6 months and 5 of them (3.7%) proved to have CIN 2 or 3. None of 59 patients who had normal findings at 6 months had histological evidence of CIN when reevaluated at 12 months. The cumulative risk of CIN 2 or 3 after 12 months was 12.2%. Using any grade of CIN as the clinical end point, the cumulative rate was 27.9%. Of those women with initially normal findings who had high-grade CIN discovered during follow-up, about 80% had low-grade squamous intraepithelial lesion or normal cytology.The frequency of CIN 2 or 3 in these women with ASC-H was lower than previously reported rates. If future studies confirm a low rate of CIN in women with ASC-H, it might be appropriate to employ other parameters in order to decide which patients require colposcopy. It might also prove helpful to combine patients having ASC-US and those with ASC-H into a single diagnostic category.