Ovarian torsion and cyst accidents — structured SAQ (15 marks)

(a) Definition and pathophysiology (3 marks)

• Definition (1 mark): adnexal torsion is the twisting of the ovary, and usually the fallopian tube, on its ligamentous supports.
• Vascular cascade (2 marks): venous and lymphatic obstruction first (ovarian oedema and enlargement), then arterial compromise, progressing to ischaemia and, if not relieved, infarction.[3]

(b) Presentation, the whirlpool sign and the Doppler pitfall (4 marks)

• Presentation (1 mark): sudden-onset, unilateral, intermittent, nonradiating lower abdominal pain with nausea and vomiting, often a tender adnexal mass — torsion is the fifth most common gynaecologic emergency.[1]
• Whirlpool sign (1 mark): the twisted vascular pedicle appearing as a target-like or snail-shell mass of concentric coils — the most specific sonographic sign, described by Vijayaraghavan.[2]
• Doppler pitfall (2 marks): arterial flow can persist in partial or early torsion because venous flow is compromised first, so a Doppler signal does not exclude the diagnosis; the Wattar 2021 systematic review shows all imaging modalities are imperfect, so torsion remains a clinical diagnosis.[3][4]

(c) Operative management and the detorsion debate (5 marks)

• Time-critical laparoscopy (1 mark): operate on clinical suspicion; ovarian salvage falls the longer ischaemia persists, so do not delay for exhaustive imaging.[1]
• Detorsion-and-observation (2 marks): detorse the adnexa and assess viability — even a black or dusky ovary can recover because congestion and ischaemia are not necessarily irreversible necrosis; oophorectomy is reserved for frankly necrotic, non-viable tissue.[5]
• Oophoropexy (1 mark): consider in recurrent torsion, surgically-naive recurrent torsion, or when a single ovary remains.[5]
• Malignancy caveat (1 mark): if malignancy cannot be excluded, oophorectomy should ideally be by a gynaecology-oncology surgeon; characterise the cyst first.[3]

(d) Differential of the cyst accidents and IOTA (3 marks)

• Cyst rupture (1 mark): very sudden sharp pain (often at coitus or exercise), free fluid on ultrasound, cyst wall may collapse; a ruptured dermoid causes chemical peritonitis needing washout and cystectomy.
• Haemorrhagic cyst (1 mark): acute unilateral pain with a reticular 'fishnet' internal echo pattern; usually self-limiting, managed with analgesia and observation unless torsion cannot be excluded.
• IOTA (1 mark): apply the Simple Rules (five benign B-features and five malignant M-features) and the ADNEX model to characterise the underlying cyst and shape the surgical approach before operating.[6]