Flow cytometric classification of biopsy specimens from cervical intraepithelial neoplasia.

The distribution of single-cell DNA content was investigated in biopsy specimens from the human cervix of 121 women suspected of having intraepithelial neoplasia. Comparison of the results of the histopathological examination with the ploidy level showed that all normal specimens were diploid. Thus, no false-positive results occurred. Most of the specimens classified as mild and moderate dysplasia were diploid as well. Aneuploid cell populations occurred in 78% of the lesions classified as severe dysplasia and carcinoma in situ. The ploidy level distribution permitted a natural division of the aneuploid cell populations into two groups with DNA indices either above or below 1.5. The importance of the aneuploidy in carcinogenesis is discussed.