Torsion of Ovarian Cyst

Torsion of an ovarian cyst is twisting of an ovary that carries a cyst or mass around its vascular pedicle, which cuts off venous and then arterial blood supply.

• The cyst acts as the lead point; benign dermoid cysts and cystadenomas of 5 to 10 cm are common lead points.
• It is a surgical emergency; delay leads to ovarian infarction.
• Doppler flow can be normal, so a normal Doppler does not exclude torsion.

Sudden severe unilateral lower abdominal pain, often with nausea and vomiting, sometimes intermittent pain over days.

• Adnexal tenderness, a palpable mass, low-grade fever and peritonism with necrosis.
• Differential diagnosis: ruptured ovarian cyst, ectopic pregnancy, appendicitis, tubo-ovarian abscess, renal colic, degenerating fibroid, pelvic inflammatory disease.
• Complications: ovarian necrosis, peritonitis, infection, loss of the ovary, and reduced fertility.

Diagnosis is clinical, supported by ultrasound, and a normal Doppler does not exclude torsion.

• Clinical suspicion with pregnancy test.
• Transvaginal ultrasound showing an enlarged ovary with a cyst, peripheral follicles, free fluid, and the whirlpool sign of the twisted pedicle; Doppler flow may be present.
• Full blood count and C-reactive protein; MRI or CT scan only if the diagnosis is unclear and the woman is stable.
• Diagnostic laparoscopy when suspicion is high, without waiting for imaging.

Operate urgently to untwist the ovary and preserve it where possible.

• Supportive: nil by mouth; IV access and fluids; analgesia; urgent surgical review.
• Pharmacological: morphine 2.5 to 5 mg IV titrated every 5 minutes; paracetamol 1 g IV 6-hourly (maximum 4 g in 24 hours); ondansetron 4 mg IV 8-hourly. If infected or necrotic, ceftriaxone 1 g IV daily plus metronidazole 500 mg IV 8-hourly.
• Procedures: urgent laparoscopy within hours: untwist the ovary even if it looks dark or black, because function often returns. Remove the cyst at the same operation if the ovary is not oedematous, or at 6 to 8 weeks if it is very swollen. Oophorectomy only when the ovary is clearly necrotic and falls apart, or when malignancy is suspected. Send cyst contents for histology; consider oophoropexy for recurrence.
• Special groups: in pregnancy operate by laparoscopy in the second trimester, give progesterone 200 mg vaginal at night if the corpus luteum is removed before 10 weeks, and avoid ibuprofen. In girls, preserve the ovary at all costs.
• Red flags: peritonitis, fever, shock, persistent pain after detorsion.
• Follow-up: review at 1 and 6 weeks; ultrasound at 6 to 8 weeks to check ovarian size and flow; delayed cystectomy if planned.