Cellular changes in severe dysplasia of the uterine cervix progressing to malignancy.

Of a total of 1321 cases of severe dysplasia of the uterine cervix, 237 lesions (18%) were found by punch biopsy and cytological examination to have progressed to carcinoma in situ or microinvasive carcinoma later in the course of follow-up. The changes in exfoliated cells during the progression to malignancy were examined in 95 of the 237 cases. Results obtained were as follows: (1) The ratio of parabasal (immature) cells to the whole dysplastic cells gradually increased in each specimen. (2) Immature dysplastic cells showing increased nuclear membrane tension and irregular staining of the nuclear membrane gradually increased. (3) The number of immature dysplastic cells with finely or coarsely granular chromatin patterns gradually increased.