A 20-year-old woman comes to the office due to 6 hours of right lower quadrant pain. The pain came on suddenly and has become intense and constant. She has been unable to eat or drink today due to nausea and frequent vomiting. The patient has had 2 sexual partners in the last year and has a history of chlamydial cervicitis. She takes ibuprofen for dysmenorrhea on the first day of her menses. The patient has a 6-cm, right ovarian cyst, which was noted on ultrasound last year. Her last menstrual period was 3 weeks ago. Temperature is 37.2 C (99 F), blood pressure is 110/80 mm Hg, and pulse is 104/min. Abdominal examination shows tenderness to deep palpation in the right lower quadrant. Urine pregnancy test is negative. Leukocyte count is 8,000/mm³. Which of the following is the most likely diagnosis?

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Quizplus · Accepted Answer

11ec160b_3ad1_018a_9249_7fdcd557e876_MD0001_00 This patient's presentation suggests ovarian torsion, a gynecologic emergency most commonly affecting reproductive-aged women. Ovarian torsion is the partial or complete rotation of the ovary around the infundibulopelvic (suspensory ligament of the ovary) and uteroovarian ligaments, which can affect ovarian blood supply because the ovarian vessels travel in the infundibulopelvic ligament. Right-sided torsion is more common because of the greater length of the right uteroovarian ligament and because the rectosigmoid colon takes up space around the left ovary (leaving less room for movement). Risk factors include pregnancy, ovulation induction (used for infertility treatment), and ovarian masses ≥5 cm. Patients typically have lower abdominal pain (often sudden), nausea, and vomiting. Physical examination typically shows unilateral abdominal or pelvic tenderness. Peritoneal signs (rebound, involuntary guarding) and fever may develop if the ovary becomes necrotic. Initial evaluation includes complete blood count and pregnancy test (to exclude ectopic pregnancy). Leukocyte count is nonspecific because it may be normal or elevated with ovarian torsion. The diagnosis is confirmed with pelvic ultrasound showing an adnexal mass with absent Doppler flow. (Choices A and E) Appendicitis and tuboovarian abscess can cause acute right lower quadrant pain; however, both diagnoses are unlikely in this afebrile patient with no leukocytosis. (Choice B) Ectopic pregnancy can present with diffuse or localized abdominal pain and vaginal bleeding. A negative urine pregnancy test and menses occurring only 3 weeks earlier make ectopic pregnancy extremely unlikely. (Choice C) Endometriosis typically presents with chronic pelvic pain, dysmenorrhea, deep dyspareunia, and infertility. This patient's sudden onset of pain makes this diagnosis less likely. Educational objective: Ovarian torsion typically occurs in reproductive-aged women due to rotation of the ovary around the infundibulopelvic (suspensory) and uteroovarian ligaments. Patients typically have sudden-onset unilateral pelvic pain and a tender adnexal mass.

A 20-Year-Old Woman Comes to the Office Due to 6