• Inborn error of osseous development with respect to endochondral ossification
  • Lesions generally involve metaphysis and diaphysis
  • Often a predominant unilateral distribution
  • No hereditary or familial tendency


  • Presentation: Knobby swellings of the digits or gross discrepancy of length and axial alignment of extremities
  • Frequently diagnosed in childhood and adolescence.
  • M:F = 1:1
  • Lesion affecting growth plate causes angular and rotational deformities and foreshortening of limbs


  • Plain films demonstrate features of multiple enchondromatosis
  • Often expansion of overlying cortex
  • Lesions innocuous in infancy and early childhood; become more clinically worrisome with skeletal growth, causing deformity and growth disturbance
  • Development of destructive bony changes and soft tissue mass with pain suggest malignant transformation
  • Malignant changes may present simultaneously in several lesions with differing levels of activity


Histologically, lesions similar to solitary enchondroma, but may be more cellular


  • Risk of malignant degeneration to chondrosarcoma difficult to state with confidence; rare disease with no good longitudinal studies of patients at risk
    • However, risk of developing malignancy may be as high as 25% over the patient’s lifetime
  • The most common malignant transformation is to low- or medium-grade chondrosarcoma