Diagnostic performance of p16 staining in atypical squamous cells 'cannot exclude high-grade squamous epithelial lesion' in predicting high-grade cervical pathology.

Atypical squamous cells 'cannot exclude high-grade squamous epithelial lesion' (ASC-H) cytology represents clear risk and has been a controversial issue in clinical practice. The objective of this study is to investigate the diagnostic performance of p16(INK4A) immunohistochemistry (IHC) among ASC-H Pap smears in predicting high-grade cervical intraepithelial lesions. Decolourisation and staining process with p16(INK4A) is applied to 27 ASC-H diagnosed conventional Pap smears, which were all managed with colposcopy-directed cervical biopsy priorly. Staining characteristics of ASC-H Pap smears were compared with histopathological data and sensitivity-specificity values of p16 triage to detect CIN2 + histopathology were determined. The sensitivity and specificity of positive p16(INK4A) immune staining to detect CIN2 + histopathology were as 87.5% and 68%, respectively. The positive predictive value of p16 triage is found as 53.8% and negative predictive value was as 92.8%. p16(INK4A) IHC seems applicable for conventional Pap smears and may provide an alternative triage option in ASC-H category.