Correlation of the histologic appearance of intraepithelial neoplasia of the cervix with human papillomavirus types. Emphasis on low grade lesions including so-called flat condyloma.

Cervical condylomas and intraepithelial neoplasia (CIN) were correlated with human papillomavirus (HPV) types and analyzed for the presence of abnormal mitotic figures. Colposcopically directed cervical biopsies were divided in half and processed for routine microscopy and Southern blot hybridization. Of 83 specimens from 71 patients, 70 (84%) contained HPV-DNA sequences. The HPV distribution was as follows: HPV 16 in 6/25 flat condylomas (FC), 2/8 CIN I, 8/18 CIN II, 12/14 CIN III; HPV 18 in 1/25 FC; HPV 31 in 3/25 FC, 3/18 CIN II, and 1/14 CIN III; HPV 6/11 in 12/18 exophytic condylomas (EC), 5/25 FC, 2/8 CIN I, and 3/18 CIN II. Uncharacterized HPVs were identified in 4/18 EC, 5/25 FC, 2/8 CIN I, and 1/18 CIN II. A similar heterogeneous distribution of HPV types was found in flat condylomas and CIN I. A more homogeneous distribution was noted in the exophytic condylomas and high grade CIN lesions, with HPV 6/11 found in the former and predominantly HPV 16 in the latter. Abnormal mitotic figures were predominantly seen in the high grade CIN lesions. Based on our findings, we would recommend that the term flat condyloma be abandoned and that low grade flat lesions of the cervix be graded according to CIN criteria.