- Partial hydatidiform moles are more premalignant than the complete hydatidiform moles.
- GTNs are almost always curable.
- In GTNs, the uterine artery pulsatility index (PI) has been shown to predict methotrexate resistance.
- Metastases typically occur in the peritoneum.
- Uterine artery embolization (UAE) has a proven therapeutic effect in the management of post GTN vascular malformations.
Notes:16% of the complete and 0.5% of the partial moles can transform into malignant forms, i.e., invasive mole, choriocarcinoma and placental site trophoblastic tumour (PSTT). GTN has excellent prognosis and are almost always curable with methotrxate or actinomycin-D. USG and MRI show 'cluster of grape' or 'sand storm' appearance. GTN shows low impedence, high velocities (low PI) in the arteries. The uterine artery PI is known to predict response to chemotherapy. With the exception of vaginal disease, it is rare to have other metastatic disease in the absence of lung disease. Liver metastasis is a marker of poor outcome. Up to 15% of GTNs develop vascular malformations and UAE has been used successfully to treat them. Hyperthyroidism is a rare complication of GTN.
Reference: Allen SD et al. Radiology of gestational trophoblastic neoplasia. Clin Rad 2006:61:301-313.
