Two forms: complete and partial
Complete Mole
–46XX, all from sperm, fertilization of single egg with lostchromosomes, embryo dies very early
–Hydropic degeneration and absence of vessels in swollenvilli
–Theca lutein cysts 2° overstimulation of lutein elements byelevated HCG
Partial Mole
–Usually 69XXY, due to fertilization of one egg by two sperm
–Embryo lives for several weeks