A 20-year-old woman comes to the emergency department due to 6 hours of right lower quadrant abdominal pain. The pain came on suddenly and has become intense and constant. She has had associated nausea but no vomiting or diarrhea. The patient has a history of dysmenorrhea and underwent placement of a progestin-releasing intrauterine device (IUD) 2 months ago. Since IUD placement, she has had daily light vaginal bleeding, with a moderate increase in bleeding today. The patient has had 3 sexual partners in the last year and has a history of chlamydial cervicitis. Temperature is 37.2 C (99 F), blood pressure is 110/80 mm Hg, and pulse is 104/min. BMI is 30 kg/m2. Abdominal examination shows tenderness to deep palpation in the right lower quadrant. On pelvic examination, the IUD strings are visible at the cervix, and there is a palpable, tender right adnexal mass. Urine pregnancy test is negative. Leukocyte count is 8,000/mm3. Which of the following is the most likely diagnosis in this patient?
Ovarian torsion | |
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Clinical presentation |
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Ultrasound |
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Treatment |
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This patient's right lower quadrant pain and tender adnexal mass are classic for ovarian torsion, a gynecologic emergency due to partial or complete rotation of the ovary around the infundibulopelvic (IP) ligament. Risk factors include an ovarian mass or ovulation induction (infertility treatment).
Ovarian torsion typically presents with sudden, unilateral lower abdominal pain due to the ovary twisting acutely around the IP ligament; the twisting occludes the ovarian vessels and compromises adnexal blood supply, causing pain.
Patients may initially have partial torsion, which occurs due to oscillation between the twisted and untwisted positions (ie, causing pain, nausea, and vomiting when twisted and relief when untwisted).
Patients can progress to complete ovarian torsion, or persistent blood flow obstruction, which causes severe ischemia and tissue necrosis, resulting in intense, constant pain.
Patients with complete torsion can have a tender, palpable adnexal mass (ie, enlarged, edematous ovary) and vaginal bleeding (ie, from adnexal edema and necrosis). Due to the severity of potential complications (eg, infertility), ovarian torsion is a clinical diagnosis. Pelvic ultrasound revealing an adnexal mass with absent Doppler flow can support the diagnosis (but is not required). Management is with emergency laparoscopy to untwist the adnexa and restore blood flow.
(Choices A and E) Appendicitis can present with right lower quadrant pain and may eventually cause a mass due to abscess formation (eg, if untreated); however, this typically develops over days rather than presenting suddenly, as in this patient. In addition, although torsion can cause low-grade fever and mild leukocytosis (due to ovarian necrosis), the absence of these findings makes appendicitis and tuboovarian abscess less likely.
(Choice B) Although an ectopic pregnancy can present with lower abdominal pain and vaginal bleeding, this patient's negative pregnancy test make this diagnosis unlikely.
(Choice C) In contrast to this patient's clinical findings, endometriosis typically presents with chronic pelvic pain, dysmenorrhea, deep dyspareunia, and infertility.
(Choice F) Uterine perforation is a possible complication of IUDs and may present with severe abdominal pain. This complication is more common during or immediately after IUD placement and is less likely in this patient with visible IUD strings (which suggests normal IUD placement).
Educational objective:
Ovarian torsion occurs due to rotation of the ovary around the infundibulopelvic ligament, causing ovarian vessel occlusion and ischemia. It classically presents with acute-onset, unilateral lower abdominal pain and a tender, palpable adnexal mass. Diagnosis is clinical, and management is with emergency laparoscopy.