Introduction:
Heterotopic pregnancy is a rare condition characterized by the occurrence of two or more simultaneous pregnancies in two or more implantation sites.

Aim:
To report a case of spontaneous ectopic pregnancy co-existing with twin living intrauterine pregnancies of 10 weeks gestation.

Case study:
A 29-years-old woman 10-weeks pregnant presented to the emergency department with acute abdomen. Transvaginal ultrasound revealed di-amniotic intrauterine living twins and right adnexal mass inseparable from the ovary. Laparoscopy revealed intact right tubal pregnancy managed by salpingostomy.

Results and discussion:
Diagnosis of heterotopic ectopic is difficult as we cannot depend on bsubunit of human chorionic gonadotropin level because of the presence of a co-existent intrauterine pregnancy which affects the hormonal level and the false sense of security that may be present on visualizing an intrauterine pregnancy by ultrasonography (USG), therefore, it is important to visualize the adnexa even in the presence of an intrauterine pregnancy to avoid missing a possible co-existent ectopic pregnancy. Surgery is the gold standard treatment. Other treatment modalities as laparoscopic or transvaginal USG guided injection of hyperosmolar glucose or potassium chloride have less success rates.

Conclusions:
It is important to scan the adnexa even in the presence of an intrauterine pregnancy to avoid missing a possible co-existent ectopic pregnancy. Surgery is the gold standard treatment, however, other modalities were described with less success.