juxtacortical chondroma

Juxtacortical chondromas, also known as periosteal chondromas, are rare benign chondral tumors that arise from the periosteum of tubular bones. They are thought to account for ~2% of benign bone tumors.

Epidemiology

They tend to present around the 2 to 4 decades. There is a recognized male predilection .

Location

Typical sites include :

• proximal humerus and distal femur (70%)
• phalanges (25%)
• tibia
• radius
• ulna

Radiographic features

Plain radiograph

• may be seen as a saucerisation of the adjacent bony cortex with a sclerotic periosteal reaction
• distinct soft tissue mass may be difficult to identify
• matrix calcification may be seen in ~50% of cases; as with all chondroid lesions, this tends to be ring and arc
• most lesions are <3 cm in size

MRI

Typically seen as a soft tissue lesion abutting the cortex and may better demonstrate evidence of pressure erosion of neighboring bone. Often has a lobulated configuration. Tends to lack associated medullary bone or soft tissue edema.

Signal characteristics include :

• T1: typically iso to low signal relative to muscle 
• T2/T2*: high signal but with low signal areas representing calcification
• T1 C+ (Gd): heterogeneous and tends to show peripheral predominant contrast enhancement

Treatment and prognosis

They are benign lesions, however, may be similar in imaging and histopathologic appearance to juxtacortical chondrosarcomas. Local excision is often the treatment of choice. Once resected lesions usually do not recur.

Differential diagnosis

Imaging differential considerations include:

• periosteal osteosarcoma: lobulated margins and high T2 chondral nodules of periosteal chondroma are absent
• non-epiphyseal chondroblastoma: typically associated with reactive marrow edema on MR
• juxtacortical chondrosarcoma: often larger than 3 cm (mean size 5.5 cm)
• bizarre parosteal osteochondromatous proliferation (Nora lesion): for phalangeal lesions
• cortical desmoid: for the posteromedial distal femoral lesions
• tenosynovial giant cell tumor: for phalangeal lesions 

Siehe auch:

• kortikales Desmoid
• Chondrom
• paraossale Tumoren
• bizarre parosteale osteochondromatöse Proliferation
• juxtakortikales Chondrosarkom
• periosteal chondroma in a child

und weiter:

• Tuberositas deltoidea humeri
• periostale Tumoren
• chondroide Tumoren