Human papillomaviruses and the pathogenesis of cervical neoplasia. A study by in situ hybridization.

In a previous topographic study of cervical conization specimens, condylomatous changes were commonly present in direct contact with intraepithelial neoplasia and were always located distal (ectocervical side) to the neoplasia. Viral DNA was detected by in situ hybridization using 35S-labeled nick translated DNA probes in 50 of 70 cases (71%) which had adequate lesions: HPV-16 in 30, HPV-18 in ten, HPV-31 in six, and multiple types in four cases. HPV-6/11 was detected only once, in a multiple infection. As a rule, a positive cervix contained a single virus type, and the same virus type was found in condylomatous and neoplastic areas. The results suggest that the neoplastic process is initiated in the area of condyloma toward the endocervix and, once established, extends proximally toward the cervical canal. Capsid antigen was detected in 19 cases, indicating that a proportion of the high-grade lesions is potentially infectious.