In a woman of reproductive age and abdominal pain, a positive pregnancy test from the presence of human chorionic gonadotropin (HCG), ultrasound examination to determine if a gestational sac is present within the uterus or a mass outside the uterus, and culdocentesis with presence of blood are helpful in making the diagnosis of ectopic pregnancy. Seen here is tubal epithelium at the right, with rupture site and chorionic villi at the lower left.