Direct chromosomal preparation for studying hydatidiform moles.

This report describes a simple direct method to obtain chromosomes from hydatidiform moles. Of 24 moles, 20 have been successfully karyotyped by this method. Of the 20 cases, 14 were complete and six were partial. The karyotype of complete moles was invariably diploid. Three of the partial moles were triploid (69,XXX), but three showed diploid/tetraploid mosaicism.