Objective: To assess the prevalence and spectrum of Pap smear (PS) abnormalities in sexually active adolescents in comparison to adult women in order to determine whether management of adolescents should differ from that of adults.
Study design: Five hundred twenty-four adolescents who had an initial PS at our institution from January to September 1997 were followed for 36 months with repeat PS and/or cervical biopsy. Initial PS results were compared with those of adult women. The chi 2 test was used to calculate the statistical significance of differences between the two groups. The qualified atypical squamous cells of undetermined significance (ASCUS) cytologic diagnosis in adolescents was correlated with follow-up data.
Results: The overall prevalence of squamous intraepithelial lesions (SILs) in adolescents was 29% as compared to 23% in adults. Almost all initial squamous lesions were ASCUS and low grade squamous intraepithelial lesion (LSIL); only one case of high grade squamous intraepithelial lesion (HSIL) was detected. On follow-up 18% and 2.4% of adolescents developed LSIL and HSIL, with a LSIL/HSIL ratio of 8/1 as compared to 5/1 in adults. The average time from initial PS to detection of HSIL was 20 months. All patients with HSIL except one had had one or more previous abnormal PSs. The positive predictive values (PPVs) for subsequent dysplasia for ASCUS favor reactive (ASCUS.R), ASCUS not otherwise specified (ASCUS.NOS) and ASCUS favor dysplasia (ASCUS.D) in adolescents were .13, .17 and .31, respectively. ASCUS.NOS (P = .01) and ASCUS.D (P = .007) were strong indicators of dysplasia as compared to ASCUS.R.
Conclusion: PS abnormalities are more common in sexually active adolescents, with a significantly higher prevalence of LSIL over HSIL as compared to adult women. Given the natural history of HPV infection, we recommend follow-up with cytology rather than colposcopy/biopsy for adolescents with ASCUS and LSIL PSs. Qualification of ASCUS is useful in determining which adolescents are at the highest risk of cervical dysplasia.