Background: The frequency of high-grade cervical intraepithelial neoplasia (CIN2+) among Thai women with abnormal cytology, including low-grade squamous intraepithelial lesion (LSIL), was previously reported as higher than in Western populations. The aim of this study was to evaluate the prevalence of underlying significant cervical lesions (CIN2+) in women with LSIL cytology.
Materials and Methods: A cross-sectional study was conducted among Thai women who participated in a screening program at the women’s health clinic at Chulabhorn Hospital, Thailand, between July 2011 and August 2013. A total of 63 women with LSIL cytology were recruited for colposcopic evaluations.
Results: A total of 63 women with LSIL smear were included; the median age was 38 years (22 to 67 years). Most women were multiparous (61.9%) and premenopausal (80.9%). After colposcopic evaluations, the histological results were as follows: 7 (11.1%) cases with CIN2, CIN3 or adenocarcinoma in situ; 18 (28.6%) with CIN1; 32 (66.7%) with no epithelial lesion; and no cases with cervical cancer. No clinical factors were found to correlate with high-grade cervical lesions.
Conclusion: The rates of high-grade cervical lesion (CIN2+) at initial colposcopy following LSIL cytology in our population were lower than reported in previous studies.

Keywords: Prevalence, Cervical intraepithelial neoplasia (CIN), Low-grade squamous intraepithelial lesion (LSIL), Thailand