A 21-year-old woman comes to the emergency department due to severe right lower quadrant pain. The pain began 3 weeks ago and was initially intermittent and dull. However, over the last 4 hours the pain has become constant and severe. She is now having nausea and vomiting, but no diarrhea or dysuria. The patient has no chronic medical conditions and has had no surgeries. She has regular, monthly menses, and her last menstrual period was 2 weeks ago. Temperature is 37.8 C (100 F), blood pressure is 140/70 mm Hg, and pulse is 93/min. BMI is 19 kg/m². Abdominal examination reveals right lower quadrant tenderness with rebound and guarding. Pelvic examination shows scant physiologic cervical discharge and no cervical motion tenderness. A tender, right adnexal mass is palpated. Pregnancy test is negative. Pelvic ultrasound reveals a 6-cm, partially calcified, right ovarian mass with multiple thin, echogenic bands. There is decreased Doppler flow to the right ovary. Which of the following is the most likely cause of this patient's mass?

Question

A 21-year-old woman comes to the emergency department due to severe right lower quadrant pain.  The pain began 3 weeks ago and was initially intermittent and dull.  However, over the last 4 hours the pain has become constant and severe.  She is now having nausea and vomiting, but no diarrhea or dysuria.  The patient has no chronic medical conditions and has had no surgeries.  She has regular, monthly menses, and her last menstrual period was 2 weeks ago.  Temperature is 37.8 C (100 F), blood pressure is 140/70 mm Hg, and pulse is 93/min.  BMI is 19 kg/m².  Abdominal examination reveals right lower quadrant tenderness with rebound and guarding.  Pelvic examination shows scant physiologic cervical discharge and no cervical motion tenderness.  A tender, right adnexal mass is palpated.  Pregnancy test is negative.  Pelvic ultrasound reveals a 6-cm, partially calcified, right ovarian mass with multiple thin, echogenic bands.  There is decreased Doppler flow to the right ovary.  Which of the following is the most likely cause of this patient's mass?

Quizplus · Accepted Answer

11ec25c8_d9d7_ad1f_bc81_15e2ba22df54_MD0003_00 This patient has ovarian torsion, a twisting of the ovary around the supporting ligaments (eg, infundibulopelvic, utero-ovarian) containing the ovarian vessels. Torsion initially impedes venous outflow with continued arterial inflow, leading to vascular congestion and edema. Persistent torsion (as in this patient) causes acute-onset, severe pelvic pain due to ovarian ischemia and necrosis from complete ovarian vessel obstruction (eg, decreased ovarian Doppler flow) and can be complicated by peritonitis (eg, fever, nausea, vomiting) and an acute abdomen (eg, rebound, guarding). utero-ovarian Any large ovarian mass (≥5 cm) can induce torsion; however, mature cystic teratomas (also known as dermoid cysts), common in premenopausal women, have an elevated risk due to their heterogeneous composition and variable density that creates an unstable mass prone to rotation. This composition is seen on ultrasound as a partially calcified mass (eg, teeth) with multiple thin, echogenic bands (eg, hair). In case of torsion, treatment is prompt surgical detorsion to restore circulation and preserve fertility with either an ovarian cystectomy (to prevent recurrence) or oophorectomy (if necrotic). (Choice B) Endometriomas are encapsulated collections of old blood from ectopic endometrial implants on the ovary that appear as homogeneous cystic masses. There are typically no solid (eg, calcified, hyperechoic) components. Endometriomas (Choice C) Follicular cysts are physiologic cysts that are usually asymptomatic. Ovulation (ie, follicular cyst rupture) may cause unilateral pelvic pain mid-cycle (ie, mittelschmerz), with a simple, small, thin-walled cyst ± free fluid (physiologic). (Choice D) Serous ovarian cancers (eg, cystadenocarcinoma) appear as complex masses with solid components; however, they are typically not calcified or hyperechoic. (Choice E) Theca lutein cysts appear as large, bilateral cystic masses rather than a unilateral mass. They arise from markedly elevated β-hCG levels (eg, hydatidiform mole)-this patient's pregnancy test is negative, making this diagnosis unlikely. (Choice F) Tubo-ovarian abscesses (TOAs) present with fever and tender, multiloculated, cystic masses with distortion of normal adnexal structures. Although this patient does have a low-grade fever, a TOA is unlikely because there is no abnormal discharge or cervical motion tenderness. Educational objective: Ovarian torsion causes acute-onset, severe pelvic pain due to ovarian rotation impeding circulation and causing ischemia. Mature cystic teratomas (dermoid cysts) are common causes of premenopausal adnexal masses and have an elevated risk of torsion due to their heterogeneous composition. References: Detecting ovarian disorders in primary care. (http://www.ncbi.nlm.nih.gov/pubmed/24791406) Clinical risk factors for ovarian torsion. (http://www.ncbi.nlm.nih.gov/pubmed/26212687) Mature cystic teratoma of the ovary: a cutting edge overview on imaging features. (http://www.ncbi.nlm.nih.gov/pubmed/28105559)

A 21-Year-Old Woman Comes to the Emergency Department Due to Severe