HPV-Associated Cervical Neoplasia

This chapter addresses common benign changes in the cervix as well as in situ and invasive lesions associated with human papillomavirus (HPV). Metaplastic changes of both the squamous and columnar epithelium of the cervix are very common, including transitional cell metaplasia and tubal/tubo-endometrioid metaplasia. Additionally, various hyperplastic glandular proliferations may be seen, such as microglandular hyperplasia and lobular endocervical glandular hyperplasia. Cervical inflammation from various etiologies is extremely common and associated with characteristic reactive epithelial changes. Various alterations are also seen in women who are pregnant or taking exogenous hormones, for example, stromal decidualization and Arias-Stella reaction. While most of these benign findings are usually readily recognized as such, careful morphologic assessment and application of immunohistochemistry may be necessary for distinction from the preneoplastic and neoplastic entities which they may mimic. HPV-related squamous intraepithelial lesions of the cervix have undergone many changes in terminology, and are now classified as low grade (LSIL) and high grade (HSIL). HPV-related glandular intraepithelial neoplasia is termed adenocarcinoma in situ, and variations such as intestinal differentiation may be seen. Diagnosis of these lesions and distinction from benign mimics is aided by ancillary studies. Invasive HPV-related carcinomas include many subtypes of squamous cell carcinoma and adenocarcinoma. Classification systems, diagnostic criteria, and important pitfalls for all of these entities are provided. Additionally, the role of cytologic–histologic correlation and new management guidelines are briefly discussed.