Fact-sheet: Torsion of ovary
Updated on 07/09/2024 at 9:47 AM
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Definition
Torsion of ovary results from partial or complete twisting of the ovarian pedicle, containing the arteries, veins and lymphatics, around its axis, which can lead to vascular obstruction of the ovary, ischemia and ovarian necrosis.
Diagnostic and therapeutic emergency, threatens fertility prognosis
Clinical features
Mean age: 30 years
Clinical presentation: acute pelvic pain, initially unilateral, intermittent, accompanied by digestive symptoms in more than 50% of cases (nausea, vomiting)
Risk factors: ovarian mass, history of torsion, ovarian hyperstimulation syndrome, polycystic ovary syndrome, pregnancy, overly long infundibulopelvic ligament or mesosalpinx.
Ultrasound
First-line examination, performed emergently.
● Increased ovarian size: size > 4 cm, volume greater than 4–6 mL before puberty and greater than 45–60 mL after puberty, or a volume difference of 5 mL compared to the contralateral ovary.
● Peripheral location of ovarian follicles.
● Midline position of the ovary.
● Ovarian edema: with ovarian parenchyma more echogenic than the contralateral ovary.
● Ovarian mass: the presence of an ovarian mass in a setting of pelvic pain should raise suspicion for torsion of ovary until proven otherwise. Common benign lesions include hemorrhagic cysts, mature cystic teratomas, and cystadenomas (better characterized on MRI).
● Whirlpool sign: torsion coil with an inter-utero-ovarian or latero-ovarian mass.
● Tubal wall thickening.
● Hematosalpinx: dilated tubular structure with echogenic content.
● Peritoneal effusion: late sign frequently associated with hemorrhagic transformation or ovarian necrosis.
● Color Doppler:
- Absence of Doppler signal, a sign of severity reflecting ovarian ischemia.
- Early sign: absent venous flow
- Late sign: elevated arterial resistance.
CT
Contrast-enhanced abdominopelvic CT is not indicated in cases of suspected torsion of ovary in children.
Ovarian signs:
- enlarged ovary, ovarian edema and peripheral distribution of follicles,
- ovary in an abnormal position.
- Sign of severity: necrotic-hemorrhagic areas
Tubal signs:
- torsion coil, tubal wall thickening, hematosalpinx
Peritoneal signs:
- intraperitoneal effusion
- reflex ileus
MRI
Allows emergent confirmation of the diagnosis and assessment of hemorrhagic necrosis and ovarian ischemia.
MRI should not delay therapeutic management.
Ovarian signs:
- enlarged ovary, ovarian edema, and peripheral distribution of follicles,
- ovary in an abnormal, midline position
- Ovarian edema with intermediate T2 hyperintensity relative to the contralateral ovary
- Signs of severity (ischemia): diffusion hyperintensity with decreased apparent diffusion coefficient (ADC)
- Absence of ovarian enhancement on postcontrast sequences
Tubal signs:
- Whirlpool sign, tubal wall thickening
- Hematosalpinx with T1 hyperintensity
- Tubal wall thickening
Peritoneal signs:
- Intraperitoneal effusion
- Reflex ileus
- Infiltration of the periadnexal fat
- Ipsilateral uterine attraction
Management
Emergent surgical exploration
Differential diagnosis
- endometriosis nodule
- dermoid cyst
- fibrothecoma