Auxiliary and experimental diagnostic techniques for hydatidiform moles

Hydatidiform moles are classified into complete hydatidiform moles (CHMs), which are androgenetic and diploid, and partial hydatidiform moles (PHM), which are triploid with two paternal chromosomes and one maternal chromosome. The incidence of gestational trophoblastic neoplasia differs substantially between CHM and PHM. However, they are occasionally difficult to diagnose. In this review, auxiliary and experimental methods based on cytogenetic features and advanced molecular detection techniques applied to the diagnosis and analysis of hydatidiform moles are summarized, including basic principles, characteristics, and clinical implications. Short tandem repeat polymorphism analysis is considered the gold standard for the genetic diagnosis of hydatidiform moles. In clinical settings, immunohistochemical analyses of p57^KIP2 , an imprinted gene product, are widely used to differentiate CHMs from other conceptuses, including PHMs. Recently, new molecular genetic techniques, such as single nucleotide polymorphism arrays, have been applied to research on hydatidiform moles. In addition to insights from classical methods, such as chromosome analysis, recently developed approaches have yielded novel findings related to the mechanism underlying the development of androgenetic CHMs.