A 16-year-old girl comes to the emergency department with vaginal bleeding. Her last menstrual period was 12 weeks ago. She is sexually active and does not use contraception. The patient had a miscarriage last year that required a dilation and curettage. Urine pregnancy test is positive. Transvaginal ultrasound demonstrates an intrauterine gestational sac without fetal cardiac activity, and a dilation and curettage is performed. Pathology shows fetal tissue, focal trophoblastic hyperplasia, and some enlarged villi interspersed with normal villi. Which of the following is the most likely diagnosis?

Question

A 16-year-old girl comes to the emergency department with vaginal bleeding.  Her last menstrual period was 12 weeks ago.  She is sexually active and does not use contraception.  The patient had a miscarriage last year that required a dilation and curettage.  Urine pregnancy test is positive.  Transvaginal ultrasound demonstrates an intrauterine gestational sac without fetal cardiac activity, and a dilation and curettage is performed.  Pathology shows fetal tissue, focal trophoblastic hyperplasia, and some enlarged villi interspersed with normal villi.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec160b_3b1e_5ed8_9249_61c11a593173_MD0001_00 A hydatidiform mole is a premalignant gestational trophoblastic disease (GTD) characterized by abnormal placental trophoblastic proliferation, resulting in markedly elevated β-hCG levels. Molar pregnancies are benign and result from aberrant fertilization and overexpression of paternal genes. Risk factors include extremes of maternal age, prior molar pregnancy, and prior miscarriage. This patient has a partial hydatidiform mole, which typically presents in early pregnancy with vaginal bleeding and no fetal cardiac activity, similar to a miscarriage. Partial moles have a triploid karyotype (69,XXX or XXY) containing maternal and paternal DNA, with an extra chromosome set of paternal origin. Evacuated uterine contents contain fetal tissue and other parts (eg, cord, amniotic membrane), some edematous villi with focal trophoblastic proliferation, and some normal-appearing villi. A complete mole (Choice B) may also present with vaginal bleeding. In addition, the uterus is enlarged out of proportion to the gestational age, and a snowstorm pattern is pathognomonic. Pre-eclampsia, hyperthyroidism, hyperemesis, and theca-lutein cysts may be present. Cells of the evacuated tissue have a 46,XX (or rarely 46,XY) karyotype with only paternal DNA. Histologically, no fetal tissue is present, and only edematous villi are seen. (Choice A) Choriocarcinoma is a malignant GTD that can develop after any pregnancy. It often presents with vaginal bleeding and pulmonary metastases. Pathology shows sheets of anaplastic cytotrophoblasts and syncytiotrophoblasts and no villi. (Choice C) An invasive mole is diagnosed by histologic evidence of villi invading the myometrium on a hysterectomy specimen. This can be the malignant progression of a complete mole. (Choice D) A miscarriage is a pregnancy loss prior to 20 weeks gestation and presents with vaginal bleeding and low β-hCG level. Pathology would show fetal tissue and normal villi and trophoblastic tissue. (Choice F) A placental site trophoblastic tumor is a proliferation of intermediate trophoblasts. This malignant type of GTD produces human placental lactogen. Educational objective: A partial mole will have a triploid karyotype (eg, 69,XXX or XXY) and contain fetal tissue with some edematous villi with focal trophoblastic proliferation, and normal-appearing villi. Patients present with vaginal bleeding, and prior miscarriage is a risk factor. __________ References: Gestational trophoblastic disorders: an update in 2015. (http://www.ncbi.nlm.nih.gov/pubmed/26556906) Practice bulletin no. 53--Diagnosis and treatment of gestational trophoblastic disease. (http://www.ncbi.nlm.nih.gov/pubmed/15572508) Gestational trophoblastic disorders. (http://www.ncbi.nlm.nih.gov/pubmed/20673583)

A 16-Year-Old Girl Comes to the Emergency Department with Vaginal