A well-known typical feature of ectopic pregnancy is an evident gestational sac structure outside of the uterus. However, some cases show atypical appearance that is described as a heterogeneous hypervascular mass. We report two cases of ectopic pregnancy that presented heterogeneous findings mimicking gestational trophoblastic diseases but were correctly diagnosed as ectopic pregnancies on MRI. The first case was an interstitial pregnancy in which the patient underwent surgical treatment. The second case was a cesarean scar pregnancy that was treated conservatively but showed spurious enlargement of pregnancy-related lesions after the treatment. Both cases lacked myometrial invasion on MRI, and the patients were diagnosed with ectopic pregnancies. Invasive findings on MRI may discriminate ectopic pregnancy from trophoblastic tumors and avoid unnecessary hysterectomy.