Epithelioid malignancy of placental cells is a cancer separate to invasive mole (tumor comprising villous tissue), choriocarcinoma (tumor comprising mostly cytotrophoblast cells) and placenta site trophoblastic tumor (tumor comprising transformed trophoblastic cells). Epithelioid malignancy appears as a hemorrhagic solid and cystic mass. Microscopically it appears to involve mononucleated intermediate trophoblast cells surrounded by extensive necrosis.
Epithelioid malignancy is best diagnosed by histology, by an expert placental pathologist (such as Robert J. Kurman MD of Johns Hopkins Medical Center) or by a specialist at the Brewer, New England or Charing Cross Trophoblast Disease Specialty Center. Epitheliod malignancy of placental cells is an extremely rare disease.
Epitheliod malignancy like PSTT is a very slow growing malignancy and is usually very curable. The best treatment currently is surgery, such as hysterectomy.