Enchondromas are benign cartilaginous growths of the medullary cavity. Patients are typically 10-30 years old. Enchondromas are the most common benign cystic lesion to involve the phalanges, but they can appear in any bone formed from cartilage.

Radiographic findings:

• oval lucency, usually metaphyseal
• chondroid calcification (except in the phalanges)
• no periostitis

Ollier disease (enchondromatosis) is a non-hereditary condition in which patients have multiple enchondromas. The lesions can be unilateral or bilateral. With growth, these lesions may appear as "flame-shaped" linear configurations that are perpendicular to the physis. Patients often have hand and foot deformities, and are at an increased risk for malignant degeneration to chondrosarcoma.

Maffucci disease is a non-hereditary multiple enchondromatosis associated with multiple soft-tissue hemangiomas (phleboliths may be seen in soft-tissue masses on plain film). Patients with this condition have a higher rate of transformation to chondrosarcoma than patients with Ollier disease. Moreover, they are at an increased risk for malignancies of the abdomen and CNS.

Enchondromatosis (Ollier disease) shown as multiple lucent lesions. Left, AP radiograph of the left tibia and fibula demonstrates multiple enchondromas in the proximal and distal metaphyses. These lesions have a flame-shaped appearance that run perpendicular to the physes. Right, Radiograph of the left hand shows multiple enchondromas involving the phalanges of the first and second digits as well as the metacarpal of the first digit.