Gestational trophoblastic disease is a neoplasm that arises from abnormal placental tissue. There are a number of different variants of GTD, the most common types are:
Hydatidiform Moles: This is the most common type of GTD, which occurs after a woman experiences a miscarriage. This is otherwise known as molar pregnancy, and happens in about 1 out of 1000 pregnancies in the United States. These moles are slow growing tumors that look like sacs of fluid, or clusters of grapes on a sonogram. Hydatiform moles can be complete or partial moles depending upon the makeup of the sperm and egg’s DNA during conception.
Gestational Trophoblastic Neoplasia (GTN): This is a group of GTD that behaves like cancer. About half of GTN comes from molar pregnancy. About 25% comes from miscarriages or ectopic pregnancy, and about 25% follows term or preterm pregnancy. The following are different types of GTN:
Invasive moles: develop from Hydatidiform moles
Placental-Site Trophoblastic Tumors (PSTT)
Epithelioid Trophoblastic Tumors (ETT)