Role of Ancillary Techniques in Cervical Biopsy and Endocervical Curettage Specimens as Follow-Up to Papanicolaou Test Results Indicating a Diagnosis of Atypical Squamous Cells, Cannot Exclude High-Grade Squamous Intraepithelial Lesion, or High-Grade Squamous Intraepithelial Lesion

The Papanicolaou (PAP) test is widely used to screen for cervical cancer. All high-grade lesions such as atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H), and high-grade squamous intraepithelial lesion, identified on a PAP test should be followed-up by a confirmatory cervical biopsy. In this review, we discuss the challenges in interpreting cervical tissue specimens and the various ancillary techniques used in the evaluation of cervical dysplasia. Ancillary studies include deeper levels, p16 immunohistochemistry (IHC), human papillomavirus (HPV) testing, and, importantly, cyto-histologic correlation. Of these, p16 IHC is consistently sensitive and specific for detecting HSIL. HPV RNA in situ hybridization (ISH) is a newer technique with excellent sensitivity and specificity for detecting virally infected cells and it may be more broadly applicable to both low- and high-grade squamous intraepithelial lesions.