Abstract: 30 cases of condyloma acuminata were studied with electron microscopy and immuno-electronmicroscopy. Ultrastructral changes of HPV infection(koilocytosis, binucleation, giant irregular nuclei, electron dense matrix and inoreased number of swollen mitochondria) were present in high prevalence in condyloma acuminata. But no mature HPV particles were found. The koilocytosis may result from rupturing of swollen mitochondria and worn-out cytoplasmic dense matrix. Expression of HPV antigen was shown in 60% cases with gold-staining immuno-etectronmicroscopy, and in 47% cases with enzyme-staining immuno-electronmicroscopy. Therefore, the former method proved to be more sensitive than the latter one. The majority of HPV antigen possitive cells were located in the stratum granulosum and the stratum corneum.

Key words: HPV, condyloma acuminata, immuno-electronmicroscopy