Genetic Origin of a Trophoblastic Choriocarcinoma

Gestational choriocarcinoma can follow a term birth, a nonmolar abortion, or a complete hydatidiform mole. Among hydatidiform moles, heterozygous ones resulting from fertilization of an egg devoid of a nucleus by a diploid sperm (XY) or by dispermy (XX or XY) have been suggested to carry an increased predisposition to transformation to choriocarcinoma. Data on genetic analysis of choriocarcinoma are meager, being limited to cytogenetic analysis of a handful of established cell lines. Although the majority of these were heterozygous, antecedent pregnancies or molar tissues have not been investigated in any of them to clearly establish their genetic origin. We present here the results of a study of chromosomal heteromorphisms and DNA restriction fragment length polymorphisms in a choriocarcinoma, the host, her spouse, and her son from the antecedent pregnancy. Our data show that the choriocarcinoma in this case most probably arose from the product of the same fertilization that led to the antecedent pregnancy.