Uterus, Invasive complete hydatidiform mole

Invasive hydatidiform mole is uncommon, and is defined by the occurrence of a molar pregnancy (complete or partial) that invades the uterine smooth muscle and/or the vasculature. In this case, the features are of a complete hydatidiform mole (large cavitated villi, abundant trophoblast hyperplasia with both cytotrophoblast and synctitiotrophoblast cells) in which villi can be seen in the myometrium and impinging on myometrial vessels. The molar villi demonstrated loss of p57 staining in cytotrophoblast and stroma (slide not shown.)