Human papillomavirus type 31 DNA detected in part of the dysplasia but in no part of the squamous metaplasia in a specimen taken from one patient.

Using in situ hybridization, human papillomavirus (HPV 6, 16, 18, 31, 33) DNAs were detected in a cervical severe dysplasia accompanied by squamous metaplasia. It was found that, only HPV 31 DNA was harbored in the cervical severe dysplasia, but HPV DNAs were not identified in a lesion of squamous metaplasia. The in situ hybridization method will be of use, therefore, when dysplasia with squamous metaplasia or other lesions are examined for HPV DNA. In a cervical smear, HPV 31 DNA could be detected on the nuclei of dysplastic cells, so this method is applicable to cervical smears. If squamous metaplasia is to be considered as a precursor lesion to cervical dysplasia, the HPV DNA harbored in the dysplasia must also be detected in the accompanying squamous metaplasia. Our results suggested that not all squamous metaplasias were involved with HPV, as far as we were able to detect using five types of HPV DNA probe.