Version 1.0 — Published September 2026
Quick Answer
Ovarian torsion is a time-critical adnexal emergency and a high-yield NEET PG obstetrics-and-gynaecology scenario. A 24-year-old nulliparous woman with sudden right lower quadrant pain, an enlarged tender ovary on transvaginal ultrasound, and altered Doppler flow needs an 8-step approach:
- Recognise the pattern — sudden severe unilateral pelvic pain, nausea and vomiting, no fever, enlarged ovary on TVS with stromal oedema = torsion until proven otherwise
- Exclude pregnancy — urine beta-hCG mandatory (rules out ectopic; guides analgesia and imaging choices)
- Transvaginal ultrasound with colour Doppler — the imaging modality of choice; look for enlarged ovary, stromal oedema, string-of-pearls sign, decreased or absent Doppler flow, whirlpool sign
- Do not rely on preserved Doppler flow to exclude torsion — intermittent torsion and dual arterial supply can maintain flow despite twisting
- Rule out the differentials — appendicitis, ectopic pregnancy, ruptured haemorrhagic cyst, PID, endometrioma rupture, ureteric colic
- Urgent surgical consultation — laparoscopic detorsion preferred over laparotomy for fertility preservation
- Preserve the ovary — modern evidence-based practice; even black or apparently necrotic ovaries recover functionally after detorsion
- Cystectomy after detorsion — biopsy any underlying mass; oophorectomy only for frankly necrotic or malignant-appearing ovary
The case
A 24-year-old nulliparous woman, working as a graphic designer, presents to a metropolitan hospital emergency department with sudden severe right lower quadrant pain that began 5 hours ago while she was preparing dinner. The pain was initially intermittent and colicky — coming in waves every few minutes with pain-free intervals — and she attributed it to gastritis. Over the past hour the pain has become constant and severe, radiating faintly to the right lower back and inner thigh. She has had two episodes of vomiting (non-bilious, first food, then clear fluid) and feels nauseated. She denies fever, urinary symptoms, or vaginal bleeding.
Menstrual history — menarche at 13; regular 28-30 day cycles; last menstrual period 3 weeks ago; no dysmenorrhoea; no intermenstrual or post-coital bleeding.
Sexual history — not sexually active in the past 6 months; no history of sexually transmitted infection; no contraception in current use.
Past medical history — nil significant; occasional migraine headaches; no prior surgery.
Past gynaecological history — no prior pelvic imaging; no known ovarian cysts; no infertility investigation; no assisted reproductive treatment; no hormonal contraception in the past 12 months.
Family history — mother had a hysterectomy for fibroids at age 45; no ovarian, breast or endometrial cancer; no consanguinity.
Drug and social history — no regular medication; occasional paracetamol; non-smoker; occasional social alcohol; no illicit drug use.
On examination — the patient is visibly in pain, prefers to lie curled on her right side; alert and oriented. Temperature 37.5. Heart rate 105 regular. Blood pressure 118/75. Respiratory rate 18. SpO2 99 percent on room air. Capillary refill 2 seconds.
Abdomen — soft; moderate right lower quadrant tenderness with mild voluntary guarding; no rebound tenderness or rigidity; no palpable mass; Rovsing sign equivocal; Murphy sign negative; bowel sounds normal.
Bimanual pelvic examination (with a female chaperone, informed verbal consent) — external genitalia unremarkable; speculum shows a healthy pink cervix with no discharge, no cervical friability; cervical os closed; bimanual examination reveals right adnexal tenderness with a suggestion of a fullness on the right side but no discrete palpable mass; cervical motion tenderness is mild; the uterus is anteverted, mobile and normal size; left adnexa is non-tender.
Cardiovascular and respiratory — sinus tachycardia, no murmur; clear breath sounds.
CNS — alert and oriented; no focal deficit.
Working diagnosis: suspected right ovarian torsion; rule out ectopic pregnancy, appendicitis, and haemorrhagic ovarian cyst.
Initial assessment and time-critical principle
The single most important operational principle is that ovarian salvage is time-dependent — vascular compromise progresses from venous congestion (a few hours) through arterial ischaemia to infarction (typically beyond 24-48 hours, though collateral supply from the uterine artery can preserve viability longer than expected). Best functional outcomes are reported when detorsion occurs within 6-8 hours of pain onset.
A — Airway: patent, speaking full sentences.
B — Breathing: RR 18, SpO2 99 percent, no distress.
C — Circulation: HR 105, BP 118/75, mild pain-driven tachycardia; no signs of haemorrhagic shock.
D — Disability: alert and oriented.
E — Exposure: no rash, no bruising, no obvious trauma.
Initial measures — IV access (18G), IV crystalloid infusion at maintenance, urine beta-hCG, IV analgesia (morphine 0.1 mg/kg titrated), IV anti-emetic (ondansetron 4 mg), urgent transvaginal ultrasound with colour Doppler, and urgent gynaecology referral.
Tier 1 investigations (immediate)
- Urine beta-hCG — negative (rules out ectopic pregnancy; permits full range of imaging and drugs)
- CBC — Hb 13 g/dL, WBC 13,500 per microlitre with mild left shift (mild inflammatory response typical in torsion), platelets 260,000
- CRP — 22 mg/L (mildly raised)
- Renal panel and glucose — within normal limits
- Urinalysis — no leucocytes, no nitrites, no RBCs (rules out UTI, ureteric colic)
- Coagulation profile — normal (pre-operative baseline)
- Group and cross-match — 2 units on standby
- Serum electrolytes — normal
- Transvaginal ultrasound with colour Doppler — right ovary enlarged to 6 cm (compared with left 3 cm, normal for a nulliparous woman); heterogeneous stromal appearance with diffuse oedema; peripherally displaced follicles (string-of-pearls sign); a 5 cm well-defined complex cyst within the right ovary with mixed echogenicity suggesting a dermoid; markedly reduced arterial and absent central venous Doppler flow within the right ovary compared with the left; moderate free fluid in the pouch of Douglas; the appendix is identified in the right iliac fossa as a compressible blind-ending tubular structure of 5 mm without hyperaemia (normal)
Interpretation: ultrasound features highly suggestive of right ovarian torsion around a 5 cm dermoid cyst, with imaging evidence of appendix normality.
Differential diagnosis
The Indian emergency-gynaecology differential for a young woman with sudden right lower quadrant pain:
- Ovarian torsion (most likely given imaging)
- Ectopic pregnancy — ruled out by negative urine beta-hCG
- Ruptured or haemorrhagic ovarian cyst — sudden pain, often mid-cycle for a corpus luteum cyst, free fluid; usually less enlarged ovary
- Pelvic inflammatory disease (PID) — sexually active, discharge, cervical motion tenderness, fever, tubo-ovarian abscess; less consistent with this patient
- Acute appendicitis — migratory pain, low-grade fever, McBurney tenderness, ultrasound of appendix diagnostic (normal here)
- Endometrioma rupture — history of dysmenorrhoea, sudden pain, chocolate-fluid collections
- Ureteric colic — loin-to-groin colicky pain, haematuria, urolithiasis on ultrasound
- Degenerating fibroid — palpable fundal mass, pain over the fibroid, characteristic imaging
- Meckel diverticulitis — rare, distal ileal inflammation
- Constipation, mesenteric adenitis — less severe presentations
Ovarian torsion — a focused review
Ovarian torsion is the twisting of the ovary and often the ipsilateral fallopian tube around the infundibulopelvic ligament and the utero-ovarian ligament, producing vascular compromise. Venous obstruction develops first (thin-walled, low-pressure), producing stromal oedema and the classical ultrasound appearance; arterial obstruction and ischaemia follow. Complete or partial torsion may occur; intermittent torsion with pain-free intervals is a recognised pattern.
Risk factors — ovarian mass or cyst larger than 5 cm (the strongest single risk factor); pregnancy (corpus luteum, hyperstimulation, ART cycles); polycystic ovaries; developmental hypermobility from a long infundibulopelvic ligament (young girls). Right-sided torsion is more common because the sigmoid colon partially anchors the left adnexa.
Presentation — sudden severe unilateral pelvic or lower quadrant pain; nausea and vomiting are common; intermittent torsion may resolve spontaneously with detorsion and recur; low-grade fever and peritoneal signs suggest late presentation with necrosis; a palpable adnexal mass is variable.
Imaging — TVS with colour Doppler is the modality of choice. Grey-scale features — unilaterally enlarged ovary (often at least twice the contralateral side), heterogeneous stromal oedema, peripherally displaced follicles (string-of-pearls), free fluid in the pouch of Douglas. Doppler features — decreased or absent arterial and venous flow within the ovary support torsion; a whirlpool sign (twisted vascular pedicle appearing as a target-like colour Doppler pattern on transverse section) is pathognomonic when present. Preserved Doppler flow does not rule out torsion — intermittent torsion and dual arterial supply from the uterine and ovarian arteries can maintain some flow despite mechanical twisting. CT or MRI is reserved for equivocal cases and should not delay surgical management.
Diagnosis
Suspected right ovarian torsion around a 5 cm complex cyst (likely dermoid), in a 24-year-old nulliparous woman with an enlarged oedematous right ovary and altered Doppler flow on transvaginal ultrasound — for urgent operative laparoscopy, detorsion with ovarian preservation, cystectomy of the underlying lesion, and pathology of the excised cyst wall.
Management — the modern paradigm
Ovarian torsion is a surgical emergency. Delay beyond 6-8 hours risks progressive vascular compromise, though functional recovery has been documented even after 24-72 hours because of collateral supply.
Approach
- Laparoscopy is preferred over laparotomy — minimally invasive, faster recovery, less adhesion formation, better fertility preservation, direct visualisation of the pelvis, and ability to perform detorsion and cystectomy in a single sitting
- Laparotomy is reserved for very large masses, haemodynamic instability, malignancy suspected, or lack of laparoscopic expertise
Intra-operative steps
- Diagnostic pelvic survey and confirmation of torsion
- Detorsion — gentle manual untwisting of the ovarian and tubal pedicle; count the number of turns to guide fixation decisions
- Assess viability — colour recovery, pulsation, capillary bleeding after 10-15 minutes of observation; even black, cyanotic ovaries frequently recover
- Cystectomy — excise the underlying cyst if present (dermoid, functional, cystadenoma) with meticulous haemostasis and send for pathology
- Oophorectomy — reserved for a clearly necrotic non-viable ovary, strong suspicion of malignancy, elderly or postmenopausal patient, or patient who has completed family and prefers ovarian removal
- Oophoropexy — fixation of the ovary to the pelvic sidewall or the utero-sacral ligament is considered in recurrent idiopathic torsion or torsion of a normal ovary, particularly in young girls; controversial in the general population
Post-operative care
- Pain management with paracetamol plus a short course of an NSAID once haemostasis is confirmed
- Anti-emetics as required
- Early mobilisation and discharge (day 1 for uncomplicated laparoscopy)
- Pathology review of the excised cyst; oncology referral if malignancy is confirmed
- Reproductive counselling — ovarian function usually recovers; document a baseline AMH if the woman is planning fertility later
- Follow-up ultrasound at 6-12 weeks to confirm ovarian recovery
Complications
Acute
- Ovarian necrosis and loss of ovarian function if diagnosis is delayed
- Peritonitis if necrosis is extensive
- Recurrent torsion — approximately 10-15 percent risk without oophoropexy
- Sepsis — uncommon
Long-term
- Infertility — a single lost ovary in a woman with a healthy contralateral ovary usually preserves fertility; bilateral loss (rare, if torsion is bilateral or if oophorectomy is performed on the sole remaining ovary) causes surgical menopause and infertility
- Adhesions — laparoscopy reduces this compared with laparotomy
- Chronic pelvic pain — uncommon but reported
India-specific considerations
- Delayed presentation is a persistent operational issue — misattribution to gastrointestinal illness or menstrual pain, primary care unfamiliarity with the imaging features of torsion, and rural distance from tertiary care
- Underuse of transvaginal ultrasound in emergency departments outside metros — trans-abdominal ultrasound has lower sensitivity for adnexal detail, and a normal trans-abdominal scan does not exclude torsion
- Laparoscopic expertise — well-established at metropolitan tertiary centres (AIIMS, PGIMER, JIPMER, CMC, Fortis, Apollo, Manipal, Kokilaben) but variable at district and peripheral centres, where laparotomy may still be the default
- PMJAY (Ayushman Bharat) covers emergency gynaecological surgery at empanelled hospitals; laparoscopic and open procedures are both covered
- Fertility preservation counselling is under-recognised — routinely offering ovarian preservation, discussing AMH monitoring, and referring to reproductive medicine when appropriate is a growing standard
- Reproductive-age focus — the majority of Indian torsion cases are in women of reproductive age; postmenopausal torsion should raise suspicion of an underlying malignancy and prompt intraoperative frozen section
How NEET PG tests ovarian torsion
Recurring patterns:
Pattern 1 — Sudden severe unilateral pelvic pain + nausea + vomiting + enlarged ovary on ultrasound — ovarian torsion.
Pattern 2 — Commonest risk factor — ovarian mass or cyst larger than 5 cm (most often dermoid).
Pattern 3 — Right-sided predominance — because the sigmoid colon anchors the left adnexa.
Pattern 4 — Imaging modality of choice — transvaginal ultrasound with colour Doppler.
Pattern 5 — Ultrasound features — enlarged ovary, stromal oedema, peripherally displaced follicles (string-of-pearls), free fluid, altered Doppler; whirlpool sign pathognomonic.
Pattern 6 — Preserved Doppler flow — does not exclude torsion because of intermittent torsion and dual arterial supply.
Pattern 7 — Modern management — laparoscopic detorsion with ovarian preservation, cystectomy after detorsion; oophorectomy only for frankly necrotic or malignant-appearing ovary.
Pattern 8 — Differentials — ectopic pregnancy (positive beta-hCG), appendicitis (migratory pain, McBurney), haemorrhagic cyst rupture, PID, ureteric colic.
Pattern 9 — Oophoropexy — considered for recurrent idiopathic torsion or torsion of a normal ovary in young girls.
Pattern 10 — Time to detorsion — best salvage within 6-8 hours; functional recovery documented even later.
High-yield one-liners:
- The commonest cyst underlying torsion is a mature cystic teratoma (dermoid)
- Right ovarian torsion is more common than left (sigmoid protects left adnexa)
- TVS with colour Doppler is the imaging modality of choice
- Whirlpool sign — twisted vascular pedicle on colour Doppler; pathognomonic
- Preserved Doppler flow does not exclude torsion
- Detorsion with ovarian preservation is the modern standard
- Oophorectomy is reserved for a non-viable ovary, malignancy, or postmenopausal/completed-family setting
- Laparoscopy is preferred over laparotomy for fertility preservation
- Oophoropexy considered for recurrent idiopathic torsion in young girls
- Postmenopausal torsion — think malignancy until excluded
Frequently Asked Questions
What are the major risk factors for ovarian torsion in a woman of reproductive age?
Ovarian torsion is the twisting of the ovary and often the ipsilateral fallopian tube around the infundibulopelvic and utero-ovarian ligaments, causing venous obstruction first and arterial compromise later. An ovarian mass or cyst larger than 5 cm is the single strongest risk factor and is present in the majority of cases — dermoid (mature cystic teratoma), functional cysts, serous or mucinous cystadenoma and endometrioma are the commonest lesions. Pregnancy raises risk because the enlarging corpus luteum and hormonally responsive stroma increase ovarian bulk and mobility; the risk peaks in the first trimester and again with ovarian hyperstimulation from ovulation induction and assisted reproductive technology cycles. Polycystic ovaries with bilaterally enlarged ovaries are at increased risk. Developmental hypermobility from an unusually long infundibulopelvic ligament predisposes young girls to torsion of an anatomically normal ovary. Postmenopausal torsion is uncommon and, when it occurs, malignancy must be excluded. Right-sided torsion is more frequent than left because the sigmoid colon partially anchors the left adnexa.
Why is transvaginal ultrasound the imaging modality of choice and what is the whirlpool sign?
Transvaginal ultrasound is the imaging modality of choice for suspected ovarian torsion because it is fast, radiation-free, widely available in Indian emergency departments, and directly evaluates ovarian size, stromal texture, cyst content, free fluid, and vascular flow. The characteristic grey-scale features are unilateral ovarian enlargement (typically at least twice the contralateral side, often 6-12 cm), diffuse stromal oedema producing a heterogeneously echogenic appearance, and peripheral displacement of follicles giving the string-of-pearls sign. A complex cyst may be seen within the torted ovary. Free fluid in the pouch of Douglas is common. Colour and pulsed Doppler are highly specific when abnormal — decreased or absent arterial and venous flow, or absent central venous flow with preserved peripheral arterial signal, supports torsion. Crucially, preserved Doppler flow does not exclude torsion because intermittent torsion, partial torsion and dual ovarian artery supply from the uterine artery can preserve arterial signal despite mechanical twisting. The whirlpool (whirlpool sign) is the sonographic appearance of the twisted vascular pedicle in cross-section on colour Doppler — a target-like circular pattern of alternating vascular flow — and is considered pathognomonic when present.
Why has ovarian preservation replaced routine oophorectomy in the modern surgical management of torsion?
Historical teaching held that a black, cyanotic, apparently necrotic ovary at surgery must be removed to prevent thromboembolism and infection. Modern evidence has overturned that principle. Case series and prospective cohorts from the 1990s onward have shown that even severely discoloured ovaries recover functionally after detorsion, with follicular activity, hormonal function and successful pregnancies documented on long-term follow-up. The thromboembolic risk long attributed to detorsion is now recognised as extremely low and does not justify unnecessary loss of fertility. Current guidelines (ACOG, ESGE, RCOG) therefore recommend prompt laparoscopic detorsion with ovarian preservation in reproductive-age women whenever possible, followed by cystectomy of any underlying benign lesion. Oophorectomy is reserved for a clearly necrotic and non-viable ovary that fails to reperfuse, a strong suspicion of malignancy on gross appearance or frozen section, and the postmenopausal or elective-completed-family setting where risk-benefit favours removal. Prophylactic oophoropexy (fixation of the ovary to prevent re-torsion) is considered in recurrent idiopathic torsion or torsion of a normal ovary, particularly in young girls.
How is ovarian torsion distinguished from appendicitis and ectopic pregnancy at presentation?
The three diagnoses share sudden right lower quadrant pain in a young woman and are the classic emergency differential. Appendicitis typically evolves over 24-48 hours with peri-umbilical pain migrating to McBurney point, low-grade fever, anorexia and localised tenderness with rebound at McBurney point; the ultrasound shows an enlarged non-compressible blind-ending tubular structure over 6 mm in diameter with a target sign in cross-section. Ectopic pregnancy typically arises in a woman with 6-9 weeks of amenorrhoea and a positive urine beta-hCG; ultrasound shows an empty uterine cavity in the presence of a positive pregnancy test with a discriminatory beta-hCG threshold of 1500-2000 mIU/mL, possibly a tubal ring or adnexal mass separate from the ovary, and free fluid in the pouch of Douglas from tubal rupture. Ovarian torsion is sudden and severe, often intermittent early on, with nausea and vomiting; ultrasound demonstrates a unilaterally enlarged ovary with stromal oedema, peripherally displaced follicles, altered Doppler flow and free fluid. A negative pregnancy test excludes ectopic and directs the search toward torsion or appendicitis; the ultrasound then usually differentiates them. Diagnostic laparoscopy is definitive when clinical and imaging findings remain equivocal.
What is the time window for ovarian salvage and why is delayed diagnosis so damaging?
Vascular compromise in ovarian torsion progresses from venous obstruction (which produces stromal oedema, engorgement and the characteristic ultrasound appearance) to arterial compromise, ischaemia and finally infarction and necrosis. Salvage of ovarian function is time-dependent. Best outcomes are reported when detorsion occurs within 6-8 hours of the onset of pain; salvage rates decline as ischaemia extends, though functional recovery is documented even after 24-72 hours in individual cases because collateral supply from the uterine and ovarian arteries can preserve tissue viability longer than expected. Delayed diagnosis is the single most modifiable factor influencing outcome. Common reasons for delay include misattribution to gastrointestinal illness, ectopic pregnancy or appendicitis, inadequate use of transvaginal ultrasound in emergency triage, reliance on Doppler flow alone to exclude torsion (a well-known pitfall), and delays in accessing laparoscopy in peripheral centres. A high index of suspicion, early transvaginal ultrasound with colour Doppler, and prompt gynaecology referral for laparoscopy are the operational levers to reduce salvage failure and preserve fertility.
This content is for educational purposes for NEET PG exam preparation. It is not a substitute for professional medical advice, diagnosis, or treatment. Clinical information has been reviewed by qualified medical professionals.
Written by: NEETPGAI Editorial Team
Reviewed by: Pending SME Review
Last reviewed: September 2026
