Paraovarian cysts (POCs) are remnants of Wolffian duct in mesosalpinx that do not arise from the ovary. They account for ~10-20% of adnexal masses 3-4.
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They typically occur in women around the ages of 20-40 years old.
Most are asymptomatic, although patients with large lesions can present with pelvic pain.
They usually occur around the broad ligament and arise from paramesonephric, mesothelial, or mesonephric remnants. They are usually simple cysts (although some authors include paraovarian cystadenomas under the umbrella of paraovarian cysts).
A paraovarian cyst is easier to recognise if the ipsilateral ovary is demonstrated to be separate from it.
- typically thin-walled and smoothly marginated
- most often appear as unilocular 'simple' cysts (in ~66%) and rarely as multilocular (~4%)
- a soft tissue nodule in the cyst may indicate development of a neoplasm (rare) 9
Often seen located close to the ipsilateral round ligament and are often of homogenous signal intensity.
In uncomplicated cases, signal characteristics usually follow that of fluid 12.
- can be hyperintense if complicated by haemorrhage
Other features include
- may show a beak sign 11
Treatment and prognosis
Paraovarian cysts occasionally can be complicated by rupture, torsion, or hemorrhage. Large or symptomatic cysts often undergo surgical resection. Smaller asymptomatic ones are treated conservatively.
For simple paraovarian cysts with no suspicious features on ultrasound, follow-up recommendations are the same as for ovarian cysts. According to a consensus statement by the Society of Radiologists in Ultrasound 13, follow-up is recommended for cysts that are:
- 5 to 7 cm in a woman of reproductive age
- 1 to 7 cm in a postmenopausal woman
Irrespective of age, cysts larger than 7 cm warrant further evaluation (with MRI) or surgical review.
History and etymology
Paraovarian cysts are have also sometimes been referred to as paratubal cysts or a hydatid cysts of Morgagni 14,
For an adnexal cystic lesion consider:
- true ovarian cyst
- ovarian cystic neoplasm: typically has a solid component
- paraovarian cystadenoma: typically has a small solid nodule or septum
- pelvic peritoneal inclusion cyst
Ultrasound - gynaecology
- ultrasound (introduction)
- acute pelvic pain
- chronic pelvic pain
- Mullerian duct anomalies
- ovarian follicle
- ovarian torsion
- pelvic inflammatory disease
- ovarian cysts and masses
- ovarian cyst
- corpus luteum
- haemorrhagic ovarian cyst
- ruptured ovarian cyst
- ovarian epithelial tumours
- granulosa cell tumours of the ovary
- paraovarian cyst
- polycystic ovaries
- ovarian hyperstimulation syndrome
- post-hysterectomy ovary
- fallopian tube
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