Underlying Histopathology in Women with Atypical Squamous Cells of Undetermined Significance (ASC-US) Cytology in King Chulalongkorn Memorial Hospital

Abstract

Objective: To determine the prevalence of underlying significant cervical lesions and factors associated with such lesions in women with atypical squamous cells of undetermined significance (ASC-US) cytology. Materials and methods: Women with ASC-US cytology undergoing colposcopy and directed biopsy at the Department of Obstetrics and Gynecology, King Chulalongkorn Memorial Hospital between January 2007 and December 2012 were reviewed. Patients’ characteristics including histopathology were collected and analyzed. Significant cervical lesions were defined as cervical intraepithelial neoplasia grade 2 (CIN2), CIN3, adenocarcinoma in situ (AIS), and invasive cervical carcinoma. Results: During the study period 154,638 Pap smears were carried out, of which 2,136 (1.38%) were ASC-US cytology. The ratio of ASC cytology/squamous intraepithelial lesions (SIL) cytology was 1.8:1. Among 2,136 women with ASC-US cytology, 627 underwent colposcopic examination and 540 had cervical biopsy. Significant cervical lesions were noted in 46 (8.6%) women. Invasive cervical carcinoma was detected in 5 (1%) women including 3 squamous cell carcinoma and 2 adenocarcinoma. Conclusions: The underlying significant cervical lesions in women with ASC-US cytology was 8.6% and approximately 1% had invasive cervical cancer. Diagnostic work-up with colposcopy is recommended. No significant factor predicting high-grade cervical lesions was noted in women with ASC-US cytology.