Partial hydatidiform mole with diploid karyotype: report of three cases.

Recent studies suggest that a partial mole with a triploid karyotype has little tendency to invade and metastasize and usually requires no therapy other than evacuation. This report describes three patients with a mole of normal diploid karyotype coexisting with a living fetus. Each patient had persistent elevation of human chorionic gonadotropin. Two patients required chemotherapy; one of these had invasive mole. The partial mole with normal diploid karyotype is a distinct clinical entity with the potential for malignant sequelae. The possibility of twin gestation cannot be excluded.