Derived from the fertilization of an anuclear ovum by one or sometimes two haploid sperm. its molar chromosomes derive entirely from the paternal origin. it has no identifiable embryonic or fetal tissue. the chorionic villi have generalized swelling and diffuse trophoblastic hyperplasia. most complete moles (>90%) have a 46,xx karyotype and the rest 46,xy karyotype.