Molar pregnancy coexisting with a normal fetus: a case report.

Molar pregnancy with a coexisting live fetus is a rare occurrence. We present morphologic and cytogenetic analysis of a recent case. Cytogenetic studies revealed a 46, XX karyotype for the fetus, the normal placenta, and the abnormal placenta. Chromosome banding studies confirmed the presence of maternal and paternal chromosomes in all three tissues. These studies favored the possibility that both tumor and fetus arose from a single gestation. Subsequently, the patient required chemotherapy for low-risk, metastatic trophoblastic disease.