A 40-year-old woman, gravida 5, para 0, aborta 4, at 12 weeks gestation comes to the emergency department due to vaginal bleeding, midline pelvic pain, and severe nausea and vomiting. She has a history of 4 prior first trimester losses. Pelvic examination shows a 16-week-sized uterus. Speculum examination reveals dark red blood in the vagina. A β-hCG level is 100,000 mIU/mL, and an ultrasound shows no fetus and a uterine cavity filled with multiple small cysts. The patient undergoes dilation and curettage in the operating room, and a friable mass of tissue consisting of many thin-walled cysts is evacuated from her uterus. Examination of the tissue would most likely show which of the following karyotypes?

Question

A 40-year-old woman, gravida 5, para 0, aborta 4, at 12 weeks gestation comes to the emergency department due to vaginal bleeding, midline pelvic pain, and severe nausea and vomiting.  She has a history of 4 prior first trimester losses.  Pelvic examination shows a 16-week-sized uterus.  Speculum examination reveals dark red blood in the vagina.  A β-hCG level is >100,000 mIU/mL, and an ultrasound shows no fetus and a uterine cavity filled with multiple small cysts.  The patient undergoes dilation and curettage in the operating room, and a friable mass of tissue consisting of many thin-walled cysts is evacuated from her uterus.  Examination of the tissue would most likely show which of the following karyotypes?

Quizplus · Accepted Answer

11ec160b_3759_1993_9249_eb35fa655bcf_MD0001_00 A hydatidiform mole is a form of gestational trophoblastic disease and can be classified as complete or partial. This patient has a complete hydatidiform mole, which most commonly results from the fertilization of an ovum that has no maternal chromosomes by one sperm (90% of cases). The chromosomes from the haploid 23X sperm are then duplicated, forming diploid 46,XX tissue that contains only paternal DNA. 46,YY moles from duplication of 23Y sperm have not been observed, as a zygote without an X chromosome would not survive. Less commonly, 2 sperm can fertilize an empty ovum and create 46,XY tissue (Choice B). Patients with a complete mole typically present with pelvic pain and vaginal bleeding. The uterus is larger than expected for gestational age, and β-hCG levels are markedly elevated due to trophoblastic hyperplasia. An ultrasound demonstrates a central heterogenous mass with multiple cystic areas and is classically described as a "Swiss cheese" or "snowstorm" pattern. A complete mole has no fetal structures and is composed entirely of large, edematous, and disordered chorionic villi that appear grossly as clusters of vesicular structures ("bunch of grapes"). Risk factors for hydatidiform mole include extremes of maternal age, prior hydatidiform mole, prior miscarriage, or infertility. (Choice C) 47,XXX is the most common sex chromosome abnormality in females. It is usually diagnosed incidentally during genetic testing as the carriers of this genotype are typically normal. (Choice D) Klinefelter syndrome is associated with the 47,XXY karyotype and is associated with primary hypogonadism in males. It is likely due to nondisjunction of the sex chromosomes during meiotic division of the gamete of either parent. (Choices E and F) Partial hydatidiform moles have 69,XXX or 69,XXY karyotype as the result of fertilization of an ovum by 2 sperm. Partial moles typically contain fetal tissue and normal placental villi intermixed with hydropic villi. Educational objective: A complete hydatidiform mole usually results when an empty ovum is fertilized by a haploid sperm. Subsequent duplication of the paternal genetic complement (23X) results in the characteristic 46,XX genotype.

A 40-Year-Old Woman, Gravida 5, Para 0, Aborta 4, at 12