Trisomy 16 mimicking hydatidiform mole.

The authors present a case of 1st trimester miscarriage where an early, complete hydatidiform mole was clinically suspected. Histopathological and immunohistochemical analyses excluded a complete mole, but the histomorphological profile was in concordance with a partial hydatidiform mole. Genetic analysis excluded a partial mole based on biparental genome composition, where further genetic analyses detected trisomy of chromosome 16. Trisomy of chromosome 16 is a frequent cause of 1st trimester abortions and may lead to highly abnormal placental histomorphology mimicking a partial mole. Genetic analyses are crucial for proper differential diagnosis and for the determination of adequate follow-up and prognosis for further pregnancies.