BONE TUMORS
Bone tumors
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Bone tumors are classified into:
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Primary bone tumors
Secondary bone tumors ( Metastasis)
Most are classified according to the normal
cell of origin and apparent pattern of
differentiation
Bone tumors
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Bone-forming tumors
Cartilage-forming tumors
Miscellaneous tumors
Hematopoietic tumors
Fibrous tumors
Primary Bone Tumors
Bone-Forming tumors
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Osteoma
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Osteoid osteoma and
osteoblastoma
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Osteosarcoma
Cartilage-Forming tumors
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Chondroma
(Enchondroma)
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Osteochondroma
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Chondrosarcoma
Miscellaneous tumors
−
Ewing’s sarcoma
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Giant cell tumor of
bone
Cartilage Forming Tumors
OSTEOCHONDROMA
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Also called exostosis
Most common benign bone tumor
50-75% males, mean age 10 years, usually age 20 years
or less
Common; solitary or multiple
Slow growing, painful if impinges on nerve or stalk is
broken; usually stops growing and ossifies at puberty
Benign, but 1-2% of solitary tumors and 5-25% of
multiple tumors undergo malignant transformation to
chondrosarcoma.
OSTEOCHONDROMA
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Multiple hereditary exostosis: also called
osteochondromatosis; autosomal dominant
disorder.
Sites: metaphysis, not medullary cavity; usually
distal femur, proximal tibia, proximal humerus;
occasionally pelvis, scapula, ribs; rarely digits;
not in intramembranous bones
Xray: metaphyseal lesions grow in direction
opposite to adjacent joint; cortex and medulla
are continuous with underlying bone.
Osteochondroma
Morphology
•Osteochondromas are mushroom shaped and range in size from 1 to 20 cm.
•The outer layer of the head of the osteochondroma is composed of benign
hyaline cartilage varying in thickness
•Newly formed bone forms the inner portion of the head and stalk, with the
stalk cortex merging with the cortex of the host bone.
OSTEOCHONDROMA
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Gross: cartilage-capped bony outgrowth up
to 20 cm (mean 4 cm), attached to skeleton
by bony stalk, not in medullary cavity; may
have bursa around its head; cartilage cap
usually regular and thin.
Osteochondroma (exostosis)
Gross
Osteochondroma (exostosis)
Microscopic
The cap is benign hyaline cartilage, resembling disorganized growth
plate undergoing endochondral ossification. Newly formed bone forms
the inner portion of the head and stalk
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Chondroma
Benign cartilaginous tumor
Either enchondroma (arise from diaphyseal
medullary cavity), subperiosteal/juxtacortical
chondroma or soft tissue chondroma
One study claims cytofluorometric DNA
ploidy analysis is more reliable than clinical
and histologic features in distinguishing these
tumors from chondrosarcomas
2-Chondroma (enchondroma)
 30-50 yrs.
 Sporadic of inherited ( Ollier disease)
 Small bones ( hand)
 From medullary cavity
 Mature cartilage
Dr Yasir Suliman2008
Ollier disease
Dr Yasir Suliman2008
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Chondrosarcoma
Chondrosarcomas
comprise a
variety of tumors sharing the ability
to produce neoplastic cartilage
Chondrosarcoma
Gross features
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SITE;
 pelvis,
 shoulder,
 ribs.
 rarely involve the distal extremities.
Chondrosarcoma
Dr Yasir Suliman2008
Chondrosarcoma
Microscopic
These
tumors are composed of lobules of cartilage with anaplastic
chondrocytes in the lacunae and with focal enchondral ossification and
calcification.
Cartilage-forming Tumors;
Tumor Type
BENIGN
Osteochondroma
Chondroma
Chondrosarcoma
MALIGNANT
Locations
Age
Morphology
Metaphysis of long
tubular bones
10-30
Bony excrescences
with a cartilaginous
cap; may be solitary
or multiple and
hereditary
Small bones of hands and
feet
30-50
Well-circumscribed single
tumors resembling
normal cartilage; arise
with medullary cavity of
bone; uncommonly
multiple and hereditary
Bones of shoulder,
pelvis, proximal
femur, and ribs
40-60
Arise within
medullary cavity and
erode cortex;
microscopically well
differentiated
cartilage-like or
anaplastic
Giant Cell Tumor
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This is a neoplasm that contains large numbers of
osteoclast like giant cells admixed with mononuclear
cells.
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These tumors are slightly more common in females.
Giant Cell Tumor
Gross
Giant Cell Tumor
Microscopic
METASTATIC BONE TUMORS
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Metastatic tumors are the most common
malignant tumor of bone.
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Pathways of spread:
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Origin:
The radiologic appearance of metastases
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