A 27-year-old woman comes to the emergency department due to vaginal spotting. The patient recently learned she was pregnant and is at 9 weeks gestation based on a sure, regular last menstrual period. She has had dark red vaginal spotting for the past day but no abdominal pain, cramping, or passage of tissue. The patient had chlamydial cervicitis as a teenager but has no chronic medical conditions. She has started taking a daily prenatal vitamin and does not use tobacco, alcohol, or illicit drugs. Blood pressure is 120/70 mm Hg and pulse is 72/min. Pelvic examination shows a 14-week-sized uterus, a visibly closed cervix, and minimal dark red discharge from the cervical os. Urine pregnancy test is positive. Transvaginal ultrasound is shown below: Which of the following is the most likely diagnosis in this patient?

Question

A 27-year-old woman comes to the emergency department due to vaginal spotting.  The patient recently learned she was pregnant and is at 9 weeks gestation based on a sure, regular last menstrual period.  She has had dark red vaginal spotting for the past day but no abdominal pain, cramping, or passage of tissue.  The patient had chlamydial cervicitis as a teenager but has no chronic medical conditions.  She has started taking a daily prenatal vitamin and does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 120/70 mm Hg and pulse is 72/min.  Pelvic examination shows a 14-week-sized uterus, a visibly closed cervix, and minimal dark red discharge from the cervical os.  Urine pregnancy test is positive.  Transvaginal ultrasound is shown below:  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_da38_1c45_bc81_c5ee8e60771d_MD0003_00 This patient's vaginal spotting and a uterine size greater than gestational age (eg, 14 weeks size at 9 weeks gestation) are due to a complete hydatidiform mole. Complete hydatidiform mole pregnancies result from an abnormal fertilization of an empty ovum either by 2 sperm or by 1 sperm that subsequently duplicates its genome. This abnormal fertilization leads to trophoblastic proliferation and hydropic villi with no associated fetal development. The uncontrolled molar tissue proliferation and endometrial blood collection can cause first-trimester vaginal bleeding, a uterine size-date discrepancy, and markedly elevated β-hCG levels (eg, >100,000 mIU/mL). The characteristic ultrasound finding of a complete hydatidiform mole is an endometrium with a "Swiss cheese" or "snowstorm" appearance. This appearance is due to cystic hydropic villi that create a heterogenous mass with anechoic spaces but no fetus or amniotic fluid. Additional ultrasound findings may include theca lutein cysts: large, bilateral, multilocular cysts that occur due to ovarian hyperstimulation. Treatment is with suction curettage; due to the risk of malignant transformation (eg, choriocarcinoma), patients are followed with serial monitoring until the hCG level is undetectable. (Choice A) Adenomyosis, an abnormal collection of endometrial glands and stroma within the uterine myometrium, can cause a symmetrically enlarged (globular) uterus. Ultrasound may show myometrial thickening with an unaffected endometrium, not seen in this patient. (Choice B) An anembryonic gestation, a pregnancy with no embryonic development, can present with vaginal spotting. However, it typically does not cause a uterine size-date discrepancy. Ultrasound shows an empty hypoechoic gestational sac (ie, gestational sac ≥25 mm with no embryo or yolk sac). anembryonic gestation (Choice C) An ectopic pregnancy implants outside the uterus (eg, in the fallopian tube) and can present with vaginal spotting. Because there is no intrauterine pregnancy, the uterus is typically smaller than gestational age. Ultrasound shows a thin endometrium and an adnexal mass (embryo). ectopic pregnancy (Choice E) Although twin pregnancies present with a uterine size-date discrepancy, an ultrasound would show 2 fetuses rather than a "snowstorm" appearance. twin pregnancies (Choice F) Uterine leiomyoma can cause an irregularly enlarged uterus and an elevated risk of spontaneous abortion (eg, vaginal bleeding). Ultrasound shows well-circumscribed masses in the myometrium and a fetus. Uterine leiomyoma Educational objective: Complete hydatidiform moles typically present with first-trimester vaginal bleeding, uterine size greater than gestational age, and ultrasound with a "snowstorm" appearance and no fetus. References: Gestational trophoblastic disease: clinical and imaging features. (http://www.ncbi.nlm.nih.gov/pubmed/28287945) Clinical presentation of complete hydatidiform mole and partial hydatidiform mole at a regional trophoblastic disease center in the United States over the past 2 decades. (http://www.ncbi.nlm.nih.gov/pubmed/26588240) Hydatidiform mole. (http://www.ncbi.nlm.nih.gov/pubmed/29083593)

A 27-Year-Old Woman Comes to the Emergency Department Due to Vaginal