Obgyn · Year 3 · from Obgyn

Case 3: Complete Hydatidiform Mole

Patient Demographics

  • Age: 19 years
  • Sex: Female
  • Occupation: College student

Chief Complaint

"I have severe nausea and vomiting. I'm pregnant and my uterus seems too big."

History of Present Illness

The patient reports her LMP was 12 weeks ago. She has had severe nausea and vomiting for the past 6 weeks, far worse than expected "morning sickness." She has lost 10 pounds. She has had intermittent vaginal bleeding with passage of "grape-like" tissue 2 days ago. She is concerned because she "looks more pregnant than she should."

Past Medical History

  • No significant medical history
  • No prior pregnancies

Physical Examination Findings

  • Vital Signs: BP 142/88 mmHg (elevated), HR 100 bpm, Temperature 98.6F
  • General: Thin, appears uncomfortable, tremulous
  • Thyroid: Slightly enlarged, no nodules
  • Abdomen: Soft, uterine fundus palpable at umbilicus (consistent with 20-week size but patient is 12 weeks by LMP)
  • Pelvic: Small amount of blood at introitus, cervix closed, uterus dramatically large for dates, bilateral adnexal fullness

Diagnostic Workup

  • Urine pregnancy test: Strongly positive
  • Quantitative beta-hCG: 425,000 mIU/mL (markedly elevated for gestational age)
  • Hemoglobin: 10.8 g/dL
  • TSH: 0.1 mIU/L (suppressed)
  • Free T4: 2.8 ng/dL (elevated)
  • Liver function tests: Normal
  • Chest X-ray: No pulmonary nodules
  • Transvaginal Ultrasound:
  • Enlarged uterus filled with heterogeneous echogenic material
  • Classic "snowstorm" or "cluster of grapes" appearance
  • No identifiable fetus
  • Bilateral enlarged ovaries with multiple theca lutein cysts (8 cm and 6 cm)

Diagnosis

Complete Hydatidiform Mole with:

  • Markedly elevated beta-hCG
  • Uterus large for dates
  • Characteristic ultrasound findings
  • Theca lutein cysts (hCG-induced)
  • Gestational hyperthyroidism (hCG cross-reactivity with TSH receptor)
  • Hypertension (concerning for early preeclampsia, rare before 20 weeks except with molar pregnancy)

Management Plan

Pre-operative Preparation:

  • Type and crossmatch 2 units PRBCs
  • Anesthesia consultation
  • Beta-blocker (propranolol) for hyperthyroid symptoms
  • Blood pressure management

Surgical Treatment:

  • Suction dilation and curettage (D&C)
  • Performed in operating room with anesthesia support
  • Sharp curettage avoided initially (risk of perforation)
  • Oxytocin infusion started after cervical dilation to promote contraction
  • Tissue sent to pathology for confirmation

Operative Findings:

  • Large amount of vesicular tissue evacuated
  • Uterus contracted well after evacuation
  • Estimated blood loss 400 mL
  • No complications

Pathology

  • Confirmed complete hydatidiform mole
  • Hydropic villi with circumferential trophoblastic proliferation
  • No fetal tissue identified
  • p57 immunostaining negative (confirms complete mole - paternally derived)

Post-Molar Surveillance Protocol

Contraception:

  • Started on combined oral contraceptive pills
  • CRITICAL: Must avoid pregnancy during surveillance period
  • Hormonal contraception is safe and does not affect hCG interpretation

Beta-hCG Monitoring:

  • Weekly beta-hCG until undetectable for 3 consecutive weeks
  • Then monthly for 6 months
  • If levels plateau or rise: suspect gestational trophoblastic neoplasia

Clinical Course:

  • Week 1: 85,000 mIU/mL
  • Week 2: 22,000 mIU/mL
  • Week 4: 1,200 mIU/mL
  • Week 6: 45 mIU/mL
  • Week 8: <5 mIU/mL (undetectable)
  • Continued undetectable for 3 consecutive weeks

Surveillance Completion:

  • Monthly hCG for 6 additional months - all undetectable
  • Counseled that 15-20% of complete moles develop GTN requiring chemotherapy
  • She was in the 80-85% who resolved spontaneously
  • May attempt pregnancy after completing surveillance

Clinical Image

Image Description: Transvaginal ultrasound demonstrating the classic "snowstorm" or "bunch of grapes" appearance of a complete hydatidiform mole, with heterogeneous echogenic material filling the uterine cavity and no identifiable fetus.

Attribution: Image from Radiopaedia. Case courtesy of Dr. Henry Knipe. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/complete-hydatidiform-mole

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