Paraovarian Cyst

A paraovarian cyst is a cyst in the broad ligament next to the ovary, between the ovary and the fallopian tube. It arises from mesonephric or paramesonephric remnants.

• It is a recognised cause of an adnexal mass.
• It is separate from the ovary, and the ovary can be seen next to it on ultrasound.
• Most are simple and benign.

Often no symptoms; unilateral pelvic ache, pressure or a palpable adnexal swelling.

• Acute pain if the cyst twists or ruptures.
• Differential diagnosis: simple ovarian cyst, hydrosalpinx, paratubal cyst, peritoneal inclusion cyst, cystadenoma, broad ligament fibroid, ectopic pregnancy.
• Complications: torsion of the cyst with the tube, rupture, haemorrhage and, rarely, borderline tumour.

Diagnosis is by transvaginal ultrasound, showing a cyst separate from the ovary.

• Transvaginal ultrasound: a round anechoic cyst with a thin wall, clearly separate from the ipsilateral ovary, which moves independently on probe pressure.
• Pregnancy test.
• MRI if septa, solid parts or doubt about origin.
• CA-125 if the cyst has complex features.
• Histology after removal.

Observe small asymptomatic cysts, and excise large, symptomatic or complex cysts while preserving the ovary and tube.

• Supportive: reassure; analgesia; advise to report sudden pain or vomiting.
• Pharmacological: paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) and ibuprofen 400 mg oral 8-hourly with food (maximum 1.2 g in 24 hours) for 3 to 5 days.
• Procedures: observation with yearly ultrasound for cysts below 5 cm without symptoms; laparoscopic excision (cystectomy) preserving the ovary and tube for cysts of 5 cm or above, symptomatic, growing or complex. Aspiration is not advised because the cyst recurs. Emergency laparoscopy for torsion.
• Special groups: in pregnancy observe and operate only for torsion or rupture; in girls and adolescents preserve the ovary and tube; avoid ibuprofen from 28 weeks.
• Red flags: sudden severe pain with vomiting, solid areas or septa, fast growth, raised CA-125.
• Follow-up: ultrasound at 6 months, then yearly while observed; review at 2 and 6 weeks after surgery.