Melorheostosis with an associated para-articular enhancing soft tissue mass.

Melorheostosis is a rare non-hereditary sclerosing bone dysplasia which predominantly affects the appendicular skeleton. Although melorheostosis is typically recognized as an osseous lesion, associated soft-tissue components have been reported. Advanced imaging with MRI may allow for more complete evaluation of these soft tissue components; however, there is little information regarding their MRI characteristics which may lead to confusion with malignant processes. We present a case of melorheostosis in a 32-year-old woman with an associated paraarticular enhancing soft tissue mass and emphasize discriminating this from soft tissue sarcoma.