- Osteosarcoma most commonly arises in the metaphysis around the knee in children and young adults. MRI is most accurate for showing tumor extent using multiplanar views. It presents as bone destruction, new bone formation and a sunray periosteal reaction. - Chondrosarcoma mainly affects those aged 30-50 and most commonly involves the pelvis, scapulae, humerus and femur. It appears as a lytic expanding lesion containing flecks of calcium. Pelvic chondrosarcomas often have large soft tissue components. - Fibrous dysplasia may affect one or several bones and most commonly involves the long bones and ribs. It appears as a lu

1. Bone - 2
Dr Pasha Shahbaz
Shahid Sadoughi university of medical science
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2. Bone Tumors
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3. • In general, plain film radiography is the best imaging technique for making a diagnosis.
• MRI or CT delineate the :
• Full extent of a tumor
• Surrounding structures
• Relationship to the neurovascular bundle
• The main role for radionuclide bone scanning is to diagnose metastatic bone disease
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4. Primary malignant tumors
On plain films :
• poorly defined margins
• wide zone of transition
• may destroy the cortex of the bone
• A periosteal reaction is often present
• soft tissue mass may be seen.
Radionuclide bone scans show substantially increased activity in the lesion.
MRI is the most accurate technique for showing the local extent of the tumor using multiplanar
views.
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5. Osteosarcoma (osteogenic sarcoma)
• Mainly in the 5–20-year-old age group.
• Also seen in the elderly following malignant change in paget’s disease.
• Often arises in a metaphysis.
• Most commonly around the knee.
• Bone destruction
• New bone formation, and typically spiculated periosteal reaction
Is present, the so-called ‘sunray appearance’
• Elevate the periosteum to form a codman’s triangle
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6. Osteosarcoma Paget / Osteosarcoma
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7. Chondrosarcoma
• mainly in the 30–50-year-old age group.
• most commonly in the pelvic bones, scapulae ,humerus and femur.
• a lytic expanding lesion containing flecks of calcium, a sign that
indicates its origin from cartilage cells.
• diffcult to distinguish from its benign counterpart, the enchondroma.
 chondrosarcoma is usually less well defined in at least one portion
of its outline
 it may show a periosteal reaction
• Pelvic chondrosarcomas often have large extraosseus soft tissue components best seen with CT
or MRI
• may arise from malignant degeneration of a benign cartilagenous tumor
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8. Chondrosarcoma Enchondroma / Chondrosarcoma
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9. Fibrosarcoma and Malignant Fibrous Histiocytoma
• Rare
• similar histological and radiological features.
• most often present in young and middle aged adults .
• usually around the knee.
• an ill-defined area of lysis
• periosteal reaction.
• Frequently the cortex is breached
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10. Ewing’s sarcoma
• A highly malignant tumor.
• Commonest in children.
• Arising in the shaft of long bones
• Ill-defined bone destruction
• Periosteal reaction that is typically ‘onion skin’ in type .
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11. Giant cell tumor
• Has features of both malignant and benign tumors
• Locally invasive but rarely metastasis
• Most commonly around the knee or wrist
• After the epiphyses have fused
• An expanding, destructive lesion
• Subarticular in position
• The margin is fairly well defined but the cortex is thin and
May be completely destroyed
 Giant cell tumor. An eccentric expanding lytic lesion has thinned the cortex
crossed by strands of bone. The subarticular position is characteristic of this tumor
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12. Primary lymphoma of bone
• Rare
• associated with generalized lymph node disease
• When solitary primary lymphomas are encountered
they may produce sclerotic bone lesions
or they may cause destruction of bone
• indistinguishable on imaging grounds from
Fibrosarcoma /malignant fibrous histiocytoma.
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13. Benign tumors and tumor-like conditions
• an edge that is well demarcated by a sclerotic rim.
• cause expansion but rarely breach the cortex.
• There is no soft tissue mass
• Periosteal reaction is unusual unless there has been a fracture .
• Radionuclide scans in benign tumors usually show little or no increase in activity, unless a fracture has occurred.
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14. Enchondroma :
• lytic expanding lesions.
• Most commonly in the bones of the hand
• They often contain a few flecks of calcium .
• frequently present as a pathological fracture.
 Enchondroma :
• in the metacarpal, proximal and middle phalanges
• showing lytic areas that expand but do not breach the cortex
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15. Fibrous cortical defects (non-ossifying fibromas) :
• common chance findings in children and young adults.
• well-defined lucent areas in the cortex of the long bones .
• NOF > 3 cm
 NOF :
• a well circumscribed lucency in the distal diaphysis/metaphysis of the tibia.
• The margins are slightly sclerotic.
• No periosteal reaction is present.
• It does not abut the growth plate.
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16. Fibrous dysplasia :
• May affect one or several (20-30%)bones.
• Multiple fd :
• Mccune-albright
• Precocious puberty in girls
• Hyperthyroidism
• Hyperparathyroidism: renal stones, calcinosis
• Acromegaly
• Diabetes mellitus
• Cushing syndrome: osteoporosis, acne
• Growth retardation
• Mazabraud syndrome:
• Soft-tissue myxomas
• Most commonly in the long bones and ribs .
• A lucent area with a well-defined edge
• There may be a sclerotic rim around the lesion.
• May expand the bone  FD :
• Mixed lytic sclerotic lesion related to the femoral metaphysis.
• Slight bowing appears present.
• Some areas appear to have a ground-glass appearance.16

17. Mazabraud syndrome
• Diffusely abnormal irregular trabecular pattern
• Areas of increased and decreased osseous density
• Ground-glass opacity
• Moderate cortical thinning
• Endosteal irregularity
• There is no associated periosteal reaction
• There is no definitive soft-tissue mass.
• The proximal epiphysis of the right femur is spared
• Similar lesions are present within the right ilium in the
supra-acetabular region and along the iliac crest.
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18. McCune-Albright syndrome
• Extensive bony expansion
• Areas of heterogeneous bone density ranging from sclerotic
to lucent.
• The majority of affected bones demonstrate a ground-glass
appearance.
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19. Simple bone cyst :
• wall of fibrous tissue and is filled with fluid.
• Occurs in children and young adults.
• Most commonly in the humerus and femur.
• Form a lucency across the width of the bone shaft
• With a well defined edge.
• The cortex may be thin and the bone expanded
• Often, the first clinical feature is a pathological fracture.
 Bone cyst:
• There is an expanding lesion crossed by strands of
bone in the upper end of the humerus in a child.
• does not cross, the epiphyseal plate
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20. Aneurysmal bone cysts :
• are not true neoplasms.
• probably form secondarily to an underlying primary tumor.
• Mostly they are seen in children and young adults.
• in the spine, long bones or pelvis.
• These lesions are purely lytic
• cause massive expansion of the cortex, hence the name ‘aneurysmal’.
• They may grow quickly and appear very aggressive but are, nevertheless, benign lesions.
• CT and MRI may show the blood pools within the cyst.
• The major differential diagnosis is from giant cell tumor .
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21. Aneurysmal bone cyst
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22. Osteoid osteoma :
• Is a painful condition
• Most commonly in the femur and tibia
• Young adults.
• A small lucency
• Sometimes with central specks of calcifcation, known as a ‘nidus’, surrounded by a dense sclerotic rim.
• Periosteal reaction may also be present .
• Radionuclide bone scanning, which shows marked focal increased activity.
• Radionuclide bone scanning is particularly useful when the osteoid osteoma is:
• Difficult to see on plain film
• And is helpful in locating the tumor during surgery
 Osteoid osteoma :
(a) Plain flm showing an area of sclerosis at the upper end of the tibia (arrows)
(b) CT scan showing sclerosis with a central lucency known as a nidus (arrow).
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23. Osteoid osteoma
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24. Osteoma :
• Is a benign tumor
• Consisting of dense bone
• They may occur in the paranasal sinuses.
 Osteoma:
• A well-defined area of dense cortical bone is present below the right acetabulum.
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25. Osteoma
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26. Eosinophilc granuloma :
• Is the mildest and most frequent form of langerhans cell histiocytosis .
• It occurs in children and young adults .
• Produces lytic lesions
• May be single or multiple.
• Most frequently in the skull, pelvis, femur and ribs.
• Extensive lesions may be seen giving rise to the so-called ‘geographic skull’.
• Long bone lesions show :
• Bone destruction which may be ill defined, having the features of an aggressive lesion
• Or well defined and may have a sclerotic rim.
• Periosteal reaction is sometimes seen .
 EG :
• ill-defined lucency within the femoral shaft with surrounding layering
periosteal reaction. 26

27. Eosinophilc granuloma – Geographic Skull
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28. Eosinophilc granuloma
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