Primary Bone Tumors

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Primary Bone Tumors

• Courtney Gleason
• September 27, 2007

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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.

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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.

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Plain Radiographs

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

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Benign Lesions

• 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

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Malignant Lesions

• 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.
• -codmans triangle
• -onion-skinning

• Examples
• -Osteogenic sarcoma
• -Ewings sarcoma
• -Chondrosarcoma

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Enchondroma

• 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.

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Simple Bone Cyst

• 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

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Nonossifying Fibroma

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

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Osteogenic Sarcoma

• Metaphyseal region of distal femur and proximal
  tibia.
• Destroy surrounding cortices and produce soft
  tissue masses.
• Codmans triangle

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Ewings Sarcoma

• Diaphysis of femur
• Destructive, lytic lesion with permeative margins
• Onion-skinning

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References

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