1. Primary Bone Tumors Courtney Gleason September 27, 2007

2. Bone Tumors • Bone tumors can be primary or secondary. • Secondary (metastasis) tumors are the most common malignancy of bone. • Primary bone tumors are divided into benign and malignant. • Benign primary bone tumors are much more common than malignant primary bone tumors.

3. Imaging • Primary bone tumors, both benign and malignant often have specific radiographic appearances on plain film. • MRI is used for local staging and to assess the position of the tumor in the medullary canal, degree of extracortical involvement, and proximity to surrounding structures.

4. Plain Radiographs Assess for: • Precise location • Underlying bony abnormality • Well-defined margin • Cortical expansion or destruction • Periosteal reaction • Soft tissue mass

5. Radiographic findings: -Geographic pattern of bone destruction (well defined area of lysis) with a sclerotic rim. -Sclerotic rim (indicates that the bone has had time to react). -Solid periosteal reaction displaying focal cortical thickening. Examples: -Enchondroma -Aneurysmal bone cyst -Simple bone cyst -Nonossifying fibroma -Chondroblastoma Benign Lesions

6. Radiographic findings: -Permeative pattern of bone destruction displays tiny radiolucencies between residual bone trabeculae (characteristic of rapidly growing, poorly defined lesions). -Poorly defined bone pattern -Periosteum shows separation from the cortex and formation of new bone. -codman’s triangle -onion-skinning Examples: -Osteogenic sarcoma -Ewing’s sarcoma -Chondrosarcoma Malignant Lesions

7. Metaphysis of tubular bones, ie small bones of the hands and feet. Lytic geographic lesion. Well-circumscribed oval lucencies. surrounded by a thin rim of radiodense bone. Enchondroma

8. Proximal humerus and proximal femur central, well marginated & symmetric metaphysis is not broader than with width of epiphyseal plate thin rim of non-reactive bone borders the bone cyst Simple Bone Cyst

9. Metaphyseal or diaphyseal regions of distal femur or tibia. Eccentrically located, lobulated, surrounded by sclerotic margin. Nonossifying Fibroma

10. Metaphyseal region of distal femur and proximal tibia. Destroy surrounding cortices and produce soft tissue masses. Codman’s triangle Osteogenic Sarcoma

11. Diaphysis of femur Destructive, lytic lesion with permeative margins Onion-skinning Ewing’s Sarcoma

12. References • Robbins and Cotran. Pathologic Basis of Disease. 7th Edition. • UMDNJ SOM Bone Tumor Pathology website. • X-rays obtained on the web.