A 24-year-old woman comes to the emergency department due to lower abdominal cramping and vaginal bleeding. The patient started to have vaginal spotting a few days ago but has had slightly increased bleeding with painful lower abdominal cramping since this morning. She is sexually active, and her last menstrual period was 5 weeks ago. Blood pressure is 130/80 mm Hg and pulse is 100/min. Diffuse tenderness to palpation is present over the lower abdomen. On speculum examination, the cervix is closed and there is dark red blood coming from the cervical os. Bimanual examination reveals a small uterus and a 3-cm mass in the left adnexa. Quantitative serum β-hCG level is 1,200 mIU/mL (normal:

Question

A 24-year-old woman comes to the emergency department due to lower abdominal cramping and vaginal bleeding.  The patient started to have vaginal spotting a few days ago but has had slightly increased bleeding with painful lower abdominal cramping since this morning.  She is sexually active, and her last menstrual period was 5 weeks ago.  Blood pressure is 130/80 mm Hg and pulse is 100/min.  Diffuse tenderness to palpation is present over the lower abdomen.  On speculum examination, the cervix is closed and there is dark red blood coming from the cervical os.  Bimanual examination reveals a small uterus and a 3-cm mass in the left adnexa.  Quantitative serum β-hCG level is 1,200 mIU/mL (normal: <5).  Which of the following is the most likely underlying cause of this patient's presentation?

Quizplus · Accepted Answer

11ec160b_3ace_b796_9249_19d6d94f30db_MD0001_00 This patient has lower abdominal pain and vaginal bleeding. In the setting of a positive pregnancy test (eg, detectable β-hCG) and an adnexal mass, her presentation is most concerning for ectopic pregnancy. Following ovulation, the ovum normally travels along the length of the fallopian tube where it can be fertilized by a sperm cell. The fertilized ovum continues through the fallopian tube, developing into a blastocyst, and subsequently implants on the uterine endometrium. However, migration of the fertilized ovum is occasionally impeded, resulting in implantation in the fallopian tube (~90%) or other extrauterine locations. Ectopic pregnancy often occurs secondary to tubal pathology (eg, pelvic inflammatory disease, prior pelvic surgery) but can present in patients without risk factors. After implantation in the fallopian tube, the ectopic pregnancy develops into a highly vascular adnexal mass that draws blood flow from surrounding tissues to maintain its rapid growth. This causes ischemic injury to surrounding tissues, fallopian tube edema, and potential tubal rupture, resulting in the classic symptoms of pelvic cramping and vaginal bleeding (eg, spotting). (Choice A) A hydatidiform mole can occur due to abnormal ovum fertilization by 2 sperm and may present with vaginal bleeding and adnexal enlargement (ie, theca lutein cyst formation due to β-hCG stimulation). Patients typically have an enlarged uterus (due to abundant growth of chorionic villi) and markedly elevated β-hCG levels (>100,000 mIU/mL), neither of which is seen in this patient. (Choice B) Uterine leiomyoma (ie, fibroids) are tumors arising from benign proliferation of the myometrium. Although they can cause cramping and vaginal bleeding, fibroids usually present with uterine enlargement or an abnormal uterine contour, which are not seen in this patient. In addition, fibroids are not associated with elevated β-hCG levels. (Choice C) An endometrioma, or ectopic endometrial tissue in the ovary, can cause an adnexal mass and vaginal bleeding if ruptured. However, patients typically have dysmenorrhea and additional symptoms associated with endometriosis (eg, dyspareunia, dyschezia). (Choice E) Ovarian torsion can occur in patients with a mature teratoma (an ovarian mass composed of ectoderm, endoderm, and mesoderm). Although torsion can cause pelvic pain and a palpable adnexal mass, the pain is typically sudden and unilateral and vaginal bleeding is uncommon. Educational objective: Ectopic pregnancy occurs when a fertilized embryo implants in an extrauterine location (eg, the fallopian tube). Patients can have pelvic cramping, vaginal bleeding, and a palpable adnexal mass. __________ References: Incidence, diagnosis and management of tubal and nontubal ectopic pregnancies: a review. (http://www.ncbi.nlm.nih.gov/pubmed/28620520) Diagnosis and management of ectopic pregnancy. (http://www.ncbi.nlm.nih.gov/pubmed/25077500)

A 24-Year-Old Woman Comes to the Emergency Department Due to Lower