Melorheostosis is uncommon in the axial skeleton and is very rare in the ribs. Diagnosis is made radiographically with a "dripping candle wax” appearance with dense hyperostosis that flows along the cortex of the bone. When occurring in an atypical anatomical location, melorheostosis may be misinterpreted as an aggressive lesion. Typical "dripping candle wax" sign and absence of aggressive features, such as cortical disruption and/or a soft tissue component, should make imaging-based confident diagnosis of melorheostosis possible even outside the appendicular skeleton. The subtlest forms of melorheostosis present more difficulties in differential diagnosis, raising possibility of a periosteal osteosarcoma or myositis ossificans.

Radiographer: TSRM Fabio Imola