- Most common benign cystic lesion of the phalanges
- Calcified chondroid matrix except when in the phalanges (possible in phalanges but rare)
- Lack of calcified chondroid matrix anywhere else should take enchondroma off ddx
- Very difficult to differentiate from chondrosarcoma on imaging as well as on biopsy
- Therefore not routinely biopsied and more often followed with serial imaging
- Any chondroid lesion can look malignant when biopsied
- Enchondroma shouldn’t have periostitis
- Multiple enchondromas termed Ollier disease (less rare)
- Multiple enchondromas associated with soft tissue hemangiomas is known as Mafucci syndrome (rare)
Discriminators
- Must have calcification (except phalanges)
- No periostitis