[Cesarean scar ectopic pregnancy: a case report].

Ectopic pregnancy in a cesarean scar is the rarest form of ectopic pregnancy and probably the most dangerous one because of the risk of uterine rupture and massive hemorrhage. This condition must be distinguished from cervical pregnancy and spontaneous abortion in progress, so that the appropriate treatment can be immediately offered. Since the advent of endovaginal ultrasonography, ectopic pregnancy in a cesarean scar can be diagnosed early in pregnancy if the sonographer is familiarized with the diagnostic criteria of this situation, especially in women with previous cesarean scar. Here we describe a case of ectopic pregnancy in a cesarean scar in which the diagnosis was considerably late, with presentation of spontaneous regression.