Enchondroma

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)