Visual inspection with acetic acid for detection of high grade lesion in atypical squamous cells and low grade squamous intraepithelial lesions from cervical Pap smear.

Objective: To evaluate the value of visual inspection with acetic acid (VIA) test to detect high grade lesion in women with atypical squamous cells or low grade squamous intraepithelial lesions cervical cytology.

Methods: Women with atypical squamous cells or low grade squamous intraepithelial lesions who were scheduled to undergo colposcopy at Vajira Hospital and met inclusion criteria were included. All participants underwent VIA test prior to usual steps of colposcopy. The VIA results were interpreted as positive or negative using the criteria by the International Agency for Cancer Research. The standard colposcopic examination and appropriate investigations for cervical pathology were then continued. The diagnostic values of VIA test including sensitivity, specificity, positive predictive value, and negative predictive value were determined using high grade lesion including cervical intraepithelial neoplasia 2-3 and squamous cell carcinoma as a threshold.

Results: Total of 106 women was included. The VIA test was positive in 33 women (31.1%) and negative in 73 women (68.9%). Among the women with VIA test positive, 14 had high grade lesion (42.4%) while 19 had no significant lesions. Only 2/73 (2.7%) cases with negative VIA test had high grade lesion (both had cervical intraepithelial neoplasia 2). The sensitivity, specificity, positive predictive value and negative predictive value with 95% confidence interval were 87.5% (81.2 to 93.8%), 78.8% (71.1 to 86.7%), 42.4% (33.0 to 51.8%), and 97.2% (94.2 to 1.0%) respectively.

Conclusion: VIA as the intermediate test in atypical squamous cells and low grade squamous intraepithelial lesions cytology may reduce the necessity to refer some women for colposcopy.