Question: Reproductive & Endocrine Systems
A 22-year-old woman at 12 weeks' gestation by dates comes to the physician because of vaginal bleeding. Her uterus is larger than expected for gestational age. Serum beta-hCG is markedly elevated. Pelvic ultrasonography shows a heterogeneous intrauterine mass with multiple small cystic spaces and no identifiable fetus or fetal heart activity. Which of the following best describes the underlying abnormality?
Choose one answer.
Explanation
Correct answer: A. Fertilization of an empty ovum by sperm with subsequent duplication of paternal DNA
The snowstorm/cystic intrauterine mass with very high beta-hCG, a uterus large for dates, and no fetus is a complete hydatidiform mole. It typically arises when an empty ovum is fertilized and the genome is entirely paternal (often 46,XX from duplication of a single sperm), so no fetal tissue forms. A partial mole is triploid with fetal parts; ectopic pregnancy implants outside the uterus; choriocarcinoma is the malignant trophoblastic tumor that can follow a mole.
Learning objective: Distinguish a complete hydatidiform mole by its genetics and absence of fetal tissue.
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