[Flow cytometric evaluation of DNA ploidy pattern and cell heterogeneity in cervical dysplasia and carcinoma in situ].

Using flow cytometry DNA ploidy was evaluated in 77 cases with cervical dysplasia and 35 cases with squamous cell carcinoma in situ (CIS, small cell type or intermediate cell type) to investigate changes that may characterize the genomic process leading to the development of cervical squamous cell carcinoma. The co-efficient of variation (CV) in the DNA histogram for fresh human leucocytes ranged from 0.7% to 1.2%, and that for dysplasia or CIS was 3.6% on the average. DNA aneuploidy was observed in 77.8%, 93.3%, 100%, and 97.1% of the cases with mild dysplasia (n = 9), moderate dysplasia (n = 3), severe dysplasia (n = 47), and CIS (n = 35), respectively. Heterogeneity (No. of aneuploid populations > or = 2) was seen in 11.1%, 23.3%, 76.6%, and 28.6% of the cases in each histological type, respectively. While aneuploid populations with a DNA index above 1.5 (and around 2.0) were frequently observed in the cases with severe dysplasia, these were not frequently observed in the cases with squamous cell CIS. It is suggested that the heterogeneity observed in severe dysplasia is an expression of enhanced genomic instability which leads to evolution of multiple tetraploidized populations in this precursor.