Hydatidiform mole


Key Information

Appropriate Tests


Hydatidiform moles may be partial or complete (classical).

Virtually all complete hydatidiform moles have a diandric paternal-only genome with 46, XX diploid karyotype from fertilisation of an empty ovum by one spermatozoon (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 spermatozoa (90%) or 1 spermatozoon 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 (Beta HCG quantitation).

Histological assessment of aborted or curetted material is confirmatory.

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



Persistent mole





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

Go Back

Page last updated:

Copyright © 2021 RCPA. All rights reserved.