Angiosarcoma of the humerus presenting with fluid-fluid levels on MRI: a unique imaging presentation.

Fluid-fluid levels are a known feature of a number of osseous lesions, but have never before been described in primary osseous angiosarcoma, which is itself a rare malignancy. We report a case of humeral angiosarcoma presenting with fluid-fluid levels. Recognizing this entity as a possible etiology for fluid-fluid levels could help radiologists to avoid potential confusion in the differential diagnosis on imaging.