Increased risk of malignant transformation of hydatidiform moles in older gravidas: a cytogenetic study.

Cytogenetic studies were performed in 35 cases of complete hydatidiform mole, and the results were correlated with maternal age and other clinical parameters. The rate of occurrence of aneuploid cells in the 18- to 39-year age group was 19% of the total cells; the rate in the 43- to 52-year age group was 25%. The rate of aneuploid cells between 2n and 3n was 20% in the latter group but only 7% in the former group. Aneuploid cells were not found in normal villi but were found to predominate in invasive mole and choriocarcinoma. These results suggest that hydatidiform mole may have a greater potential for malignant transformation in patients 40 years and older than in younger patients.