Tetraploid partial hydatidiform mole: a case report and review of the literature.

Distinction of hydatidiform moles from nonmolar specimens and their subclassification as complete (complete hydatidiform mole) versus partial hydatidiform mole (PHM) are important for clinical practice and investigational studies to refine ascertainment of risk of persistent gestational trophoblastic disease, which differs among these entities. Immunohistochemical analysis of p57 expression, a paternally imprinted maternally expressed gene on 11p15.5, and molecular genotyping are useful for improving diagnosis.