The cervical lesion shown is similar to that obtained in a cone cervical biopsy from a 28-year-old sexually active woman who had had a "positive" Pap smear. The type of cervical change seen here is often characterized by

The illustration demonstrates carcinoma in situ of the uterine cervix, which is characterized by disordered epithelial growth manifested by loss of polarity and nuclear hyperchromasia beginning at the basal layer and extending outward. Although mild forms can be reversible, the principal significance of CIN is its precursor role in the genesis of invasive cervical carcinoma. Invasion and metastases are not associated with CIN but only with fully developed invasive carcinoma. However, genomic integration of HPV DNA sequences, most often types 16, 18, 31, or 33 is associated with CIN, as well as with frank malignant change.