Ultrasound and MRI Findings of Twin Pregnancies with Complete Hydatidiform Mole and Coexisting Normal Fetus: Two Case Reports.

BACKGROUND: Both twin pregnancies with complete hydatidiform mole and coexisting normal fetus (CHMCF) and partial hydatidiform mole can be found in association with a live fetus and a placenta displaying a molar degeneration. Two cases of CHMCF using magnetic resonance imaging (MRI) for a diagnosis are reported. CASE: In the first, CHMCF was suspected at 12 weeks of gestation. At 18 weeks of gestation, the existence of molar placenta and a sac separating from fetus and normal placenta was clearly depicted on MRI. At 19 weeks of gestations, she had termination of pregnancy because of a development of gestational trophoblastic neoplasia (GTN) and started chemotherapy. In the second case, CHMCF was suspected at 14 weeks of gestation. MRI demonstrated the existence of molar placenta and a sac separating from fetus and normal placenta. She chose induced abortion and there was no evidence of GTN during the 1 year-follow up period. Pathological examination in both cases was consistent with a complete hydration mole and a coexisting normal female fetus. CONCLUSION: MRI was useful for an accurate diagnosis for CHMCF.