A decidual cast often presents as tissue passed per vaginum between menarche and menopause.

Features of a decidual cast:

(1) The tissue is a "cast" of the uterine cavity.

(2) It consists primarily of decidualized endometrium.

(3) There is no evidence of placental or fetal tissue.


Risk factors for a decidual cast:

(1) oral contraceptive or hormonal therapy

(2) ectopic pregnancy

(3) pregnancy in a didelphic uterus


In a patient with ectopic pregnancy the decidual cast needs to be distinguished from an intrauterine pregnancy on ultrasonography. An intrauterine pregnancy will show a gestational sac with a fetal pole.

To read more or access our algorithms and calculators, please log in or register.