Morphology combined with HER2 D-DISH ploidy analysis to diagnose partial hydatidiform mole: an evaluation audit using molecular genotyping
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Aims: A hydatidiform mole (HM) is classified as complete (CHM) or partial (PHM) based on its morphology and genomic composition. Ancillary techniques are often
required to confirm a morphologically suspected PHM diagnosis. This study sought to evaluate the clinical accuracy of PHM diagnosis using morphological assessment
supported by HER2 dual-colour dual-hapten in-situ hybridisation (D-DISH) ploidy determination.
Methods: Over a 2-year period, out unit examined 1265 products of conception (POCs) from which 103 atypical POCs were diagnosed as PHM or non-molar
conceptuses with the assistance of HER2 D-DISH ploidy analysis. We retrospectively audited a sample of forty of these atypical POCs using short tandem repeat (STR)
genotyping. DNA extracted from formalin-fixed paraffin-embedded tissue was genotyped using twenty-four polymorphic loci. Parental alleles in placental villi were
identified by comparison to those in maternal decidua. To identify triploid PHM cases, we sought three alleles of equal peak height or two alleles with one allele peak twice
the height of the other at each locus.
Results: Thirty-six of the forty cases (19 PHM and 17 non-molar) were successfully genotyped and demonstrated complete concordance with the original diagnosis. All
PHMs were diandric triploid of dispermic origin. In two non-molar diploid cases, we identified suspected trisomies (13 and 18), which potentially explains the pregnancy
loss in these cases.
Conclusions: This study validates the use of HER2 D-DISH ploidy analysis to support the diagnosis of a morphologically suspected PHM in our practice.
required to confirm a morphologically suspected PHM diagnosis. This study sought to evaluate the clinical accuracy of PHM diagnosis using morphological assessment
supported by HER2 dual-colour dual-hapten in-situ hybridisation (D-DISH) ploidy determination.
Methods: Over a 2-year period, out unit examined 1265 products of conception (POCs) from which 103 atypical POCs were diagnosed as PHM or non-molar
conceptuses with the assistance of HER2 D-DISH ploidy analysis. We retrospectively audited a sample of forty of these atypical POCs using short tandem repeat (STR)
genotyping. DNA extracted from formalin-fixed paraffin-embedded tissue was genotyped using twenty-four polymorphic loci. Parental alleles in placental villi were
identified by comparison to those in maternal decidua. To identify triploid PHM cases, we sought three alleles of equal peak height or two alleles with one allele peak twice
the height of the other at each locus.
Results: Thirty-six of the forty cases (19 PHM and 17 non-molar) were successfully genotyped and demonstrated complete concordance with the original diagnosis. All
PHMs were diandric triploid of dispermic origin. In two non-molar diploid cases, we identified suspected trisomies (13 and 18), which potentially explains the pregnancy
loss in these cases.
Conclusions: This study validates the use of HER2 D-DISH ploidy analysis to support the diagnosis of a morphologically suspected PHM in our practice.
Date Issued
2025-04-17
Date Acceptance
2024-01-17
Citation
Journal of Clinical Pathology, 2025, 78 (5), pp.327-334
ISSN
0021-9746
Publisher
BMJ Publishing Group
Start Page
327
End Page
334
Journal / Book Title
Journal of Clinical Pathology
Volume
78
Issue
5
Copyright Statement
© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY. Published by BMJ Group. https://creativecommons.org/licenses/by/4.0/This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. See: https://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
10.1136/jcp-2023-209269
Publication Status
Published
Date Publish Online
2024-03-30