HSS Ultrasound Case 74

Clinical History 22 year old female with progressive lateral knee pain after prior ACL reconstruction and lateral meniscal repair MRI showed a large multilobulated lateral parameniscal cyst

Ultrasound of the Month – Case 74

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Ultrasound of the Month – Case 74

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Ultrasound of the Month – Case 74

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Ultrasound of the Month – Case 74

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Diagnosis: Parameniscal cyst of the knee.

Discussion Parameniscal cyst is a ganglion cyst arising from the meniscus due to a chronic tear of the meniscus.

Fluid leaks out from the meniscal tear into the extraarticular soft tissues and becomes confined by a pseudocapsule.

As the cyst slowly enlarges, it can become symptomatic as it causes mass effect on surrounding soft tissues.

Definitive treatment for parameniscal cysts is to surgically treat the underlying meniscal tear.

A non-invasive percutaneous treatment option is aspiration and fenestration under ultrasound guidance. Performing the procedure under ultrasound allows the radiologist to directly visualize the cyst, needle, and relevant soft tissues including the popliteal artery in the current case.

Cortisone is often injected at the end of the procedure, although the extra benefit of cortisone in preventing recurrence of parameniscal as well as ganglion cysts in general is controversial.

Ultrasound of the Month – Case 74

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