Chondromas

Chondromas are benign cartilaginous tumors composed of mature hyaline cartilage. They arise in bone (enchondromas and periosteal or juxtacortical chondromas) or in soft tissue, and can be solitary or multiple. Multiple chondromas occur in disorders such as Ollier disease (enchondromatosis) and Maffucci syndrome (enchondromas with vascular abnormalities). Enchondromas are the most common type and are typically located within the medullary cavity of short bones in the hands and feet, though they can occur in any bone. Periosteal chondromas arise on the bone surface beneath the periosteum, usually involving long bones. Soft tissue chondromas are rare extraskeletal lesions.

Most chondromas are asymptomatic and found incidentally. When symptoms occur, they may include a slow-growing swelling or pain, particularly after fracture or during growth. Imaging commonly shows well-defined lytic lesions with calcifications. Enchondromas often display rings-and-arcs calcifications and may cause endosteal scalloping with cortical thinning. Periosteal chondromas present as surface-based lesions with cortical saucerization. Soft tissue chondromas appear as calcified soft tissue masses. MRI helps delineate extent and relationship to adjacent structures.

Differential diagnosis includes chondrosarcoma, which is suggested by pain, growth, cortical destruction, a soft tissue mass, or aggressive imaging features. Treatment is typically surgical: curettage with bone grafting for enchondromas; excision for periosteal or soft tissue chondromas. Observation may be appropriate for asymptomatic lesions in skeletally immature patients if radiographs remain stable. Prognosis after complete excision is generally excellent, though recurrence can occur, and multiple or syndromic chondromas carry higher risk of recurrence or malignant transformation.