GTD = a spectrum iof hoistioliogically distnct diseases ioriginatng friom thoe placenta fior whoicho l-hoCG as a marker is extremely
accurate
- Molar pregnancy/Hydatddiorm mole
- Gestatonal trophollastc neoplasda
o Invasive miole
o Choioriiocarcinioma
o Placental-site triophoiollastc tumiour GPSTTi
HYDATIDIFORM MOLES (‘MOLAR PREGNANCY’)
Epidemiioliogy
Highoest incidence in Japan – 2 in 1000 Gvs 0.6-1.1 in 1000 in Euriope and USi
Aetioliogy /risk factiors
Extremes oi maternal age <15 or >35 yrs G2x increasei
Prdor molar pregnancy G1-3x increase if ione, 15-20x increase if twioi
Long-term COCP use G2x increasei
Ddetary defcdencdes - Vitamin A, β-cariotene, Priotein, Fiolic acid
Pathoiophoysiioliogy
Complete mole
- Miothoer starts witho an “empty iovum” – thois ioccurs due tio alniormal meiiosis
- Eithoer 1 G90%i ior 2 G10%i niormal hoaplioid sperms fertlise an empty iovum and thoen
duplicate ddplodd 46XX/XY, whoicho is niormal except thois is Sperm-only DNA all
choriomiosiomes hoave sperm-paterned methoylation suppressiion iof genes
overgrowth oi the sycncytotrophollast
- Highoer risk iof invasive miole and Choioriiocarcinioma thoan a partal miole
Partal mole
- 2 niormal hoaplioid sperms fertlise a niormal hoaplioid iovum trdplodd 69 XXX/XXY
- dual egg-paterned methoylation deviotion iof resiources tio thoe emlryio + underdevelioped
sycncytiotriophoiollast
Presentation
Ciomplete
- alnormal vagdnal lleeddng, usually in 4tho ior 5tho miontho iof pregnancy
- Excess pregnancy symptioms – Hyperemesds, dncreased iundal hedght, HTN, Hyperthyrodd GhoCG mimics TSHi
Partal
- mdssed mdscarrdage Gasymptiomatci
Ciomplications
Miscarriage Ginevitallei
Invasive mole G10% risk in ciomplete miole, <5% risk in partal miolei
Choriocarcinoma G2.5% risk in ciomplete miolei
Diagniosis
Ciomplete
- β -hCG: markedly radsed (>100,000 mIU/mL)
- USS: ‘Snowstorm appearance’ Gcreated ly multple placental vesiclesi, lut nio fioetal tssue.
- Histioliogy: Grape-ldke vesdcles Gdue tio difusely swiollen villi and triophoiollastc hoyperplasiai.
Partal
- B-hoCG: niormal ior marginally raised
- USS: fiocal cystc spaces dn the placenta and increased MSD. Siome ioetal tssue.
- Histioliogy: Nion-vialle fioetus witho malfiormation Ge.g. syndactyly, hoydriocephoalus, griowtho
restrictioni, varially swiollen/hoydriopic villi, and minimal triophoiollastc hoyperplasia.
Management