Reproductive · Year 2 · from Reproductive
Case 1: Gestational Trophoblastic Disease (Molar Pregnancy)
Clinical Image
Source: Wikipedia - Hydatidiform mole - CC BY-SA 3.0
Case Presentation
A 38-year-old G3P2 woman at 10 weeks gestation by last menstrual period presents with vaginal bleeding and severe nausea and vomiting. She reports that her symptoms of pregnancy have been much more severe than her previous pregnancies. Physical examination reveals a uterus palpable at 16-week size (large for dates), no fetal heart tones are detected by Doppler, and blood pressure is 148/94 mmHg. Laboratory studies show beta-hCG of 285,000 mIU/mL (markedly elevated for gestational age), TSH 0.1 mIU/L (suppressed), and free T4 elevated. Transvaginal ultrasound reveals an enlarged uterus filled with heterogeneous echogenic material containing multiple anechoic spaces giving a "snowstorm" or "bunch of grapes" appearance, with no identifiable fetus or gestational sac. Bilateral ovaries contain multiple theca lutein cysts (5-6 cm each). The diagnosis is complete hydatidiform mole. After evaluation shows no evidence of metastatic disease (chest X-ray negative), suction dilation and curettage is performed. Pathology confirms complete molar pregnancy (villi with diffuse trophoblastic hyperplasia, no fetal tissue, 46,XX karyotype - all paternal). Serial beta-hCG monitoring shows appropriate decline, reaching undetectable levels by 8 weeks. She is counseled to avoid pregnancy for 6 months during surveillance.
Key Learning Points
- Molar pregnancy results from abnormal fertilization: complete mole (46,XX, all paternal chromosomes, no fetal tissue) versus partial mole (69,XXX or XXY, triploid, some fetal tissue present)
- hCG is produced by syncytiotrophoblast; markedly elevated hCG in molar pregnancy can cause hyperthyroidism (hCG shares structural similarity with TSH) and theca lutein cysts (hCG stimulates ovarian follicles)
- Risk of progression to gestational trophoblastic neoplasia requires post-evacuation surveillance with serial beta-hCG monitoring
- Complete moles have higher malignant potential (15-20%) than partial moles (1-5%)