Intrauterine pseudogestational sac in ectopic pregnancy.

Ultrasonic diagnosis of ectopic pregnancy has been thought to depend on exclusion of intrauterine pregnancy on the basis of absence of an intrauterine gestational sac. Two cases illustrating intrauterine echoes suggesting a gestational sac associated with ectopic pregnancy and a plausible explanation for this phenomenon are presented. Because of this and the rare possibility of coexisting intrauterine and extrauterine pregnancies, the ultrasonographer must be wary of dismissing the possibility of an ectopic pregnancy because of an intrauterine gestational sac, whether real or apparent.