DNA contents in serous ovarian tumors of 46 cases were measured by microspeetro-photometry and compared with histological assessment of the same tumor. All. tumors had been histologically classified as serous ovarian cystadenoma in 10 cases

borderline serous cystadenoma in 11 cases and serous cystadenocarcinoma in 25 cases. The results showed that DNA contents in cytadenoma group were within 4c (23 arbitrary units)

in the borderline group were from 4c to 5c

in the cystadenocarcinoma group

some DNA contents exceeded 8c

(p<0.001). The mean nuclear size cf above 3 groups were 46.74

59.49

and 76.01 respectively

(p<0.001). of the 46 cases only one previously diagnosed borderline tumor was rccla-ssified as invasive carcinoma

we suggested that adenecarci-noma should be diagnosed in case of DNA contents above 30 arbitrary units

nuclear size above 65 and percentage of aneuploidy cells with DNA>5c above 50% accompanying with seme DNA>8c