Hydatidiform mole

Last updated: Friday, 06, August, 2010
Key InformationAppropriate Tests

Hydatidiform moles may be partial or complete (classical).

Virtuall all complete hydatidiform moles have a diandric paternal-only genome with 46, XX diploid karyotype from fertilisation of an empty ovum by one spermatozoa (90%) or 46 XX or XY from fertilisation of an empty egg simultaneously by 2 spermatozoa (10%).  Partial moles are triploid and result from fertilisation of a normal ovum by 2 heterozygous spematozoa (90%) or 1 spermatozoa with duplication (10%).  Although assessment of whether the genotypic profile is homozygous or heterozygous should distinguish between 90% of complete or partial moles, molecular genetic testing is not routinely undertaken.

The diagnosis is suggested by clinical features, diagnostic imaging and increased Human chorionic gonadotrophin (beta subunit) levels.

Histological assessment of aborted or curetted material is confirmatory.

Serial beta human chorionic gonadotrophin estimations for up to 12 months are recommended, to confirm complete removal and/or detect recurrence.


Persistent mole


Reference:Bifulco et al. Am J Surg Pathol. 32: 445-51, 2008