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Ovarian Cysts & Ovarian Torsion

Adnexal cysts are common and often functional, but enlarged ovaries or masses can twist around the vascular pedicle causing sudden severe unilateral pelvic pain and surgical emergency

Review date
reviewed 2026-05-04
Reading time
8 min read
Author
Dr Kola Tytler MBBS CertHE MBA MSt MRCGP
Obstetrics & Gynecologycommonacute
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Condition details
Obstetrics & Gynecology
common
8 min read
reviewed 2026-05-04
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About This Page

This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.

Key points

  • Functional ovarian cysts are common and often resolve spontaneously
  • Torsion classically presents with sudden severe unilateral pelvic pain, nausea, and vomiting
  • Risk rises with adnexal masses >5 cm, especially dermoids and benign cysts
  • Pelvic ultrasound with Doppler is first-line, but normal Doppler flow does not exclude torsion
  • Suspected torsion requires urgent laparoscopy with detorsion and ovarian preservation when possible

Overview

Ovarian cysts include functional cysts, hemorrhagic cysts, endometriomas, dermoids, cystadenomas, and malignancies. Torsion occurs when the ovary twists around its vascular pedicle, first compromising venous then arterial flow.

Epidemiology

Functional cysts are common in reproductive years. Torsion can occur at any age but is more common in reproductive-age patients and pregnancy. Benign masses, especially dermoids, are frequent lead points.

Clinical Features

Symptoms
Functional cyst: unilateral pelvic discomfort or incidental finding
Hemorrhagic rupture: sudden unilateral pain after intercourse/exertion
Torsion: sudden severe unilateral pain with nausea/vomiting
Intermittent pain may reflect torsion-detorsion
Fever or purulent discharge suggests PID/TOA
Signs
Adnexal tenderness or palpable mass
Peritoneal signs with rupture, hemorrhage, or torsion
Cervical motion tenderness suggests PID/ectopic depending on context
Tachycardia/hypotension with hemoperitoneum
Postmenopausal adnexal mass is higher risk

Investigations

First-line
Pregnancy testExclude ectopic pregnancy
Transvaginal ultrasound with DopplerFirst-line; torsion may show enlarged ovary, peripheral follicles, free fluid, twisted pedicle, reduced/absent flow
CBC and urinalysisAssess anemia, infection, urinary mimics
Second-line
Tumor markersSelective for suspicious masses, especially postmenopausal
MRI pelvisIndeterminate adnexal mass or planning
STI testingIf PID/tubo-ovarian abscess in differential
Specialist
Diagnostic laparoscopyDefinitive diagnosis and treatment for suspected torsion
Gynecologic oncology referralSuspicious solid components, papillary projections, ascites, metastases, high-risk postmenopausal mass

Management

ACOG Guidance on Adnexal Masses and Adnexal Torsion
1
Simple ovarian cysts
  • Observation with repeat ultrasound for many asymptomatic simple cysts
  • NSAIDs for pain
  • Hormonal contraception prevents some new functional cysts but does not reliably resolve existing cysts
  • Surgery if persistent, large, symptomatic, complex, or suspicious
2
Hemorrhagic cyst rupture
  • Stable patient: analgesia, observation, repeat evaluation if worse
  • Unstable or ongoing hemorrhage: surgery/resuscitation
  • Exclude ectopic pregnancy
3
Ovarian torsion
  • Urgent OB/GYN consultation and laparoscopy
  • Detorsion with ovarian preservation whenever possible
  • Cystectomy for benign lead point when feasible
  • Oophorectomy only if nonviable or malignancy suspected
4
Suspicious adnexal mass
  • Risk-stratify by age, menopause, ultrasound, symptoms, tumor markers
  • Refer to gynecologic oncology before surgery if high risk

Complications

  • Ovarian necrosis: Delayed torsion treatment can compromise viability
  • Hemoperitoneum: Ruptured hemorrhagic cyst can bleed significantly
  • Infertility: Loss of ovary/tube or severe endometriosis
  • Recurrence: Possible with persistent masses/elongated ligaments
  • Missed malignancy: Complex postmenopausal masses need careful evaluation
USMLE Step 2 CK Exam Tips
  • 1Sudden unilateral pelvic pain + nausea/vomiting + adnexal mass = torsion
  • 2Normal Doppler flow does not rule out torsion
  • 3Next best step for suspected torsion = urgent laparoscopy
  • 4Always get pregnancy test in reproductive-age pelvic pain
  • 5Dermoid cysts are classic torsion lead points
  • 6Simple functional cyst in stable premenopausal patient = observation/repeat ultrasound
  • 7Ruptured hemorrhagic cyst can mimic ectopic; beta-hCG distinguishes

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Verified Sources & References

ACOG Committee Opinion — Adnexal Torsion in Adolescents
ACOG Clinical Guidance — Adnexal Masses
ACOG Clinical Guidance
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