Sensitivity of koilocytosis, immunocytochemistry, and electron microscopy as compared to DNA hybridization in detecting human papillomavirus in cervical and vaginal condyloma and intraepithelial neoplasia.

The sensitivity in detecting human papillomavirus (HPV) by histological observation of koilocytosis, immunocytochemistry, and electron microscopy with reference to the results of Southern blot deoxyribonucleic acid (DNA) hybridization were reviewed in 41 lesions (37 patients) of cervical and vaginal condylomata acuminata and intraepithelial neoplasia. Human papillomavirus DNA was demonstrated in fresh tissues by Southern blot DNA hybridization in all but one lesion of moderate dysplasia (98%). The rate of koilocytosis observed in tissue sections was 80% in condyloma, and ranged from 89-20% in cervical intraepithelial neoplasia (CIN), with steady reduction as the grade of CIN or vaginal intraepithelial neoplasia (VaIN) was higher. The immunocytochemistry for HPV capsid antigens was positive in 80% of condylomata and ranged from 61-0% in CIN or VaIN. The rate declined in inverse proportion to the grade of CIN or VaIN. Electron microscopy of preselected areas containing intranuclear inclusions in paraffin sections of 10 lesions demonstrated HPV-like particles in 90% of the lesions. Although immunocytochemistry and observation of koilocytosis may be useful in detecting HPV in condylomata acuminata and mild dysplasia, their sensitivity was poor in CIN or VaIN of higher grades. Electron microscopy on preselected areas in paraffin blocks showed better sensitivity, presumably due to its ability to detect immature virions.