The tumours occur most frequently in the extremities but may also be found in the flat bones, such as those of the pelvis. Affected bones may be shortened and deformed. Children with enchondromatosis may be susceptible to pathologic fractures, and adults may be at risk of malignant transformation to chondrosarcoma.

Radiographically, the tumours may appear as linear or columnar radiolucent regions in the metaphyses or flat bones, which represent sites of persistent cartilaginous tissue (Fig.1). Erosion and proliferation of the bone surface are sometimes observed.

A nonhereditary enchondromatosis with soft tissue haemangiomas that may undergo malignant transformation is known as Maffuccis syndrome.