Thyroid storm caused by a partial hydatidiform mole.

Clinical thyrotoxicosis is rare in molar pregnancy and has yet to be reported in a patient with a partial mole. Human chorionic gonadotropin (hCG), which has thyrotropic activity, is believed to be responsible for hyperthyroidism of gestational trophoblastic activity and hyperemesis gravidarum. We report the first case of hyperthyroidism presenting as thyroid storm in a partial molar pregnancy.