Gestational Trophoblastic Disease
Gestational trophoblastic disease (GTD) is a spectrum of proliferative disorders of trophoblastic tissue after abnormal conception. It ranges from relatively benign forms like hydatidiform moles (partial, complete, or coexistent) to more malignant forms like invasive mole or choriocarcinoma.
Complete moles typically have no fetus, a normal diploid karyotype (46XX), and proliferating trophoblastic tissue without fetal development. Partial moles often show an abnormal fetus or fetal demise, a triploid karyotype (69XXY), and fetal parts may develop alongside abnormal trophoblastic tissue. Coexisting moles, which are rare, present as a normal fetus with normal placenta separate from a molar pregnancy.
Clinically, patients often present with vaginal bleeding in the first or early second trimester, dramatically elevated serum beta-hCG levels often>100,000IU/ml, and notably low maternal serum alpha-fetoprotein MS−AFP. Other findings may include hyperemesis gravidarum, preeclampsia, bilateral adnexal fullness, and a uterus larger than expected for gestational age.
Laboratory Correlation: Dramatically elevated serum beta-hCG levels often>100,000IU/ml combined with low maternal serum alpha-fetoprotein strongly suggest gestational trophoblastic disease rather than a normal pregnancy.