We have studied six cases of choriocarcinomas in the female by convent
ional cytogenetic analysis and by in situ hybridization using a 12p pa
inting probe, and found evidence for chromosome 12 abnormalities in tw
o of them. Abnormalities of chromosome 12 are a common occurrence in g
enitourinary tumors of the female, but their significance is not known
. We discuss the present findings in relation to those in malignant ov
arian germ cell tumors (MOGCTs).