KEY FACTS
Terminology
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Cyst originating from wolffian duct in mesosalpinx or broad ligament
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Synonym: Paratubal cyst
Imaging
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Transvaginal ultrasound is study of choice
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Round or oval cystic structure separate from ovary
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Unilocular in 95%, multilocular in 5%
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Mean diameter: 40 mm (range: 15-120 mm)
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Thin outer wall (< 3 mm)
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Often unilateral
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Lack of follicles distinguishes from ovary; usually does not indent ovary
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Fluid anechoic in 91%
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Rarely may be complicated by torsion or hemorrhage
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May contain septa that are thin, smooth, complete
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MR
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Hypointense on T1WI and hyperintense on T2WI
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If complicated by torsion or hemorrhage, hyperintense on T1WI with thick walls
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If soft tissue component, consider neoplasm
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Avascular on color Doppler
Top Differential Diagnoses
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Peritoneal inclusion cyst
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True ovarian cyst
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Hydrosalpinx
Pathology
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Benign serous cyst in 98%
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Malignant features in 2%
Clinical Issues
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10-20% of all adnexal masses
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Asymptomatic in most women
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Torsion, growth, and malignancy are rare complications
Diagnostic Checklist
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MR superior for identification of normal ovary when origin of large lesion cannot be determined with ultrasound
Scanning Tips
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Confirm that cyst is separate from ovary by gently pushing with vaginal probe
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Consider torsion if cyst is painful, large, and displaced
next to a normal ovary 
. They were separable with probe pressure.
, next to a normal ovary 
. They were separable from each other and from the uterus 
with probe pressure.
in the anterior pelvis. Neither ovary could be seen. MR was obtained for further evaluation.
, anterior to a fibroid uterus 
. Ovaries were normal, indicating that the cyst was a paraovarian cyst. Due to its size, surgery was performed.
