Hydatidiform Mole

This is a hysterectomy specimen which has been opened to reveal a hydatidiform mole. Hydatidiform moles are an abnormal pregnancy in which only a placenta develops containing only paternally derived chromosomes. The placental villi are enlarged and swollen. This abnormality occurs in only 1 in 1200 pregnancies. Most hydatidiform moles resolve completely after evacuation by suction curettage. Rarely, moles will persist after attempts at evacuation and require treatment with chemotherapy. The malignant counterpart of a hydatidiform mole is choriocarcinoma.