A stiff hip : multi-modality imaging of tumoral calcinosis

Abstract

Clinical History: A 40-year-old male with end-stage kidney disease (ESKD) presented following a history of a few months of increasing painless swelling of the left hip. Imaging Findings: An initial plain radiograph showed significant heterotopic calcification overlying the left hip joint. A nonenhanced CT of the left hip confirmed a large, multilobulated, periarticular calcific mass containing fluid-fluid levels. A sedimentation sign was also present. There was no soft tissue erosion. An MRI of the pelvis was performed, demonstrating encapsulated and well-circumscribed soft tissue masses around both hip joints together with a small amount of surrounding fluid. There was no additional soft tissue component. The masses were of homogeneous low signal intensity on T1-weighted imaging and of mixed-signal intensity on T2 weighted imaging with internal fluid-fluid levels mirroring the CT findings of sedimentation sign. Intravenous gadolinium could not be administered due to the impaired renal function.