A 26-year-old female acutely develops lower abdominal pain and vaginal bleeding. While in the bathroom she passes a cast of tissue com- posed of clot material and then collapses. She is brought to the hospital, where a physical examination reveals a soft, tender mass in right adnexa and pouch of Douglas. Histologic examination of the tissue passed in the bathroom reveals blood clots and decidualized tissue. No chorionic villi or trophoblastic tissue are present. Which one of the following conditions is most likely present in this individual?
a. Aborted intrauterine pregnancy
b. Complete hydatidiform mole
c. Ectopic pregnancy
d. Endometrial hyperplasia
e. Partial hydatidiform mole