HSS Ultrasound of the Month Case 120

Clincial History 32 year old male with history of ankylosing spondylitis presenting with a painful palpable mass anteriorly just below the knee.

Diagnostic ultrasound evaluation was requested.

Ultrasound of the Month – Case 120

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Ultrasound of the Month – Case 120

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Ultrasound of the Month – Case 120

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Diagnosis: Pretibial Abscess Discussion An abscess is a fluid collection containing infectious material/pus, usually due to a bacterial infection.

Chronic underlying disease such as an inflammatory arthritis, or immunosuppressive therapy may be a predisposing factor.

On ultrasound, an abscess manifests as a fluid collection that is complex in appearance (thickened wall, internal echoes, internal septations) with associated hyperemia on color or power Doppler.

Ultrasound-guided aspiration is important for isolating the offending organism, and may be curative if also treated with antibiotics.

Ultrasound of the Month – Case 120

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