A 25-year-old woman presents with vaginal bleeding at 14 weeks of gestation. Ultrasound shows a 'snowstorm' appearance with no fetal parts. Serum beta-hCG is markedly elevated at 200,000 mIU/mL. Suction evacuation is performed. Karyotype of the specimen is most likely to be:

• A 46,XX (all paternal isodisomy) ✓
• B 69,XXY (diandric monogynic triploidy)
• C 46,XY (biparental diploidy)
• D 45,X (monosomy X)

Explanation

Complete hydatidiform mole is typically 46,XX (90%) with all chromosomes of paternal origin (androgenesis, duplication of haploid sperm in empty ovum). The classic presentation includes second trimester bleeding, snowstorm ultrasound, markedly elevated beta-hCG, and absent fetal parts. Partial mole is triploid (69,XXY) with fetal parts present.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.