aka Hydatidiform mole
Abnormal proliferation of pregnancy-associated trophoblastic tissue with malignant potential, can be complete or partial. Very high b-hcg.
Complete - Generalized swelling of villous tissue, diffuse trophoblastic hyperplasia; no embryonic or fetal tissue
Partial - Combination of a fetus with localized placental molar degeneration In 90% of cases, triploid; two sets of chromosomes from father and one from mother
- Bunch of grapes (multiple sonolucent vesicles 1-30 mm in diameter)
- Snowstorm appearance (multiple interfaces from tiny cysts)
- Note invasion of myometrium in invasive choriocarcinoma