Malignant tumors occurring in the diaphysis
Ewing’s sarcoma and chondrosarcoma
Benign tumors occurring in the diaphysis:
enchondroma and fibrous dysplasia
Malignant metaphysis lesions:
osteosarcoma and juxtacortical osteosarcomas
Benign conditions and tumors of metaphysis:
1. non-ossifying fibroma
2. osteoid osteoma
3. giant cell tumors
5. chondromyxoid fibroma
Benign epiphysis lesions:
chondroblastoma and giant cell tumors
Fibrous dysplasia: 3 Patterns
1. monostotic: single bone involved
2. polyostotic: multiple bones involved
3. McCune Albright syndrome: polyostotic, café-au-lait skin pigmentation, endocrinopathies
Fibrous dysplasia: histology
loose whorled pattern of fibroblastic tissue with irregular spicules of woven bone; May contain small islands of cartilage
Fibrous dysplasia: XR
large expansile medullary mass with lucent ground-glass appearance and well demarcated borders
Fibrous dysplasia is characterized by:
benign localized developmental arrest; all components of bone are present but do not mature
What pattern of fibrous dysplasia may transform to osteosarcoma?
Microscopically, what may be seen in Fibrous dysplasia?
poorly formed islets of bone ("Chinese character")
Common location of fibrous dysplasia?
Are fibrous cortical defects common?
yes: present in 30-50% of all kids >2y/o
Fibrous cortical defects: XR
"scooped out" lesion with dense borders surrounding it
**buzzowords = scalloped and sclerotic margins
Where fibrous cortical defects located?
lower femur and upper/lower tibia
**~1/2 are bilateral or multiple
What is the expected outcome of fibrous cortical defect?
Fibrous cortical defects that are > 5-6 cm:
Epidemiology of fibrous cortical defects
Adolescents with few or no symptoms except pain (usually found incidentally on radiography)
Fibrous cortical defects: gross pathology
Eccentric, sharply delineated, metaphyseal lesions
Granular or dark red
Fibrous cortical defects: likely pathogenesis
Possible injury related to fibrous cortical defect?
fractures through thinned cortex
Non-ossifying fibroma: microscopically
woven mat or storiform pattern
Solitary bone cyst: pathogenesis
Solitary bone cyst: Epidemiology + clinical presentation
Children and adolescents (usually male)
Solitary bone cysts: gross pathology
benign, fluid-filled, lytic bone lesions with thin bone margins
Solitary bone cysts: typical location
humerus or femur
Aneurysmal bone cysts: gross pathology
bloody, cystic lesions; "sponge filled with blood"
Aneurysmal Bone Cyst: location
surface of bone--usually in long bones and vertebral column (but may occur anywhere)
*(usually slow-growing, but may present with rapid expansion)
Aneurysmal Bone Cyst: microscopic pathology
rich capillary bed
Aneurysmal Bone Cyst: Epidemiology
Children and young adults
Benign tumors which may contribute to pathological fracture (3):
solitary bone cyst
aneurysmal bone cyst
fibrous cortical defect
When do Benign Primary Bone Neoplasms often present?
1st 3 decades of life
When are Benign Primary Bone Neoplasms removed?
if they cause pain
How are Benign Primary Bone Neoplasms often discovered?
What type of Benign Primary Bone Neoplasm may undergo malignant transformation?
How are Osteoma's characterized?
round, slow-growing bone-forming tumors
Osteoma: growth patterns
1. project from sub- or endosteal surfaces of cortex
2. Usually solitary (multiple = Gardner’s syndrome)
Osteoid osteoma: clinical presentation + Epidemiology
Painful, generally < 2 cm lesion occuring most commonly in teens + twenty-something's; more often in M > F (2:1)
Osteoid osteoma: location
1. cortical (rather than medullary)
2. 50% = tibia and fibula
What causes the main symptom of Osteoid osteoma? What makes it better/worse?
--Pain due to production of prostaglandin E2
--Worse: more commonly painful at night; Intake of alcohol >> massive increase in pain
How are Osteochondroma characterized?
--benign cartilage capped tumors.
--tend to be attached to underlying skeletal system by a stalk
What effects do Osteochondroma have on the skeletal system?
Displacement of growth plate in endochondral bones
What is multiple hereditary exostosis?
autosomal dominant Osteochondroma, which may rarely give rise to chondrosarcomas
How are chondroma's characterized?
Benign tumor of hyaline cartilage
Where do Enchondromas arise?
medullary cavity, often in tubular bones of hands and feet
Where do Juxtacortical chondromas arise?
on the surface of bones
Nonhereditary syndrome characterized by formation of multiple enchondromas:
Syndrome characterized by formation of multiple enchondromas and soft tissue hemangiomas:
Radiolucent nodules of hyaline cartilage + scalloped endosteal surface
Giant Cell Tumor of Bone: Epidemiology
patients in their 20's - 40's
Giant Cell Tumor of Bone: Primary lesion location? secondary lesion location?
1. around knee
2. bones of wrist
How are Giant Cell Tumor of Bone characterized?
--benign, uncommon and locally aggressive
--Multinucleated osteoclast type giant cells
--commonly undergo cystic degeneratio
Half of Malignant Bone Tumors are derived from:
blood forming cells and connective tissue cells
Most common bone tumors?
Sites from which metastases occur to the bone are characteristically:
Breast, prostate, lung, kidney and thyroid
Most common primary malignant bone tumor?
Osteosarcoma: Clinical presentation + Epidemiology (typical)
painful lesions, typically in knee joint, in patients <20; often come to attention due to secondary injury (during sports, etc)
Osteosarcoma occurs less frequently in what patient populations?
elderly, pt's w/ Paget disease of bone or pt's w/ hx of radiation
Where does osteosarcoma present in older patients?
bones of the pelvis and the bones of the skull
What conditions are osteosarcoma often associated with, clinically?
fractures, Retinoblastoma (Rb, MDM2), lung metastasis at diagnosis
Osteosarcoma grows into:
soft tissue surrounding the bone
What is the Codman triangle of periosteal elevation?
triangular shell of reactive bone formed by lifted periosteum; characteristic but not pathognomonic of osteosarcoma
Chondrosarcoma: clinical presentation + Epidemiology
lesion often in axial skeleton, in patients ages 35-60
Axial skeleton: trunk, pelvis, vertebrae, ribs (rarely involves extremities)
in diaphysis or metaphysis
Second most common primary malignant tumor?
Surgery (insensitive to chemotherapy)
Chondrosarcoma may arise in association with:
a preexisting enchondroma
Malignant bone neoplasms characteristically:
"do not respect joint spaces"
cells that mimic chondrocytes ("float" within ~chondroid matrix)
high nuclear cytoplasmic ration, nuclei and abundant mitotic figures
Ewing Sarcoma: Epidemiology
White children, ages 10 to 15
Ewing Sarcoma: microscopicaly
--very high nuclear cytoplasmic ratio (mostly nucleus) = "blue cell tumor"
--glycogen rich cells which tend to form small structures called Homer-Wright rosettes (tumor cells arranged in a circle around a central fibrillary space)
85% of Ewing Sarcoma have genetic signatures, which show they are related to:
(What is the genetic signature?)
peripheral neuroectodermal tumors
Ewing Sarcoma: gross pathology
onion skin appearance = layers of reactive periosteum and neoplasms
Ewing Sarcoma: location
Arise in medulla, primarily in diaphysis of long bones
Ewing Sarcoma: treatment and prognosis?
surgery and chemotherapy = 75% five year survival rate
Most common tumors in bone?
In adults > 75% of skeletal metastasis originate from:
prostate, breast, lung, and kidney
In children, skeletal metastasis originate from:
neuroblastoma, Wilms’ tumor, osteosarcoma, Ewing sarcoma (extraosseous) and rhabdomyosarcoma
What is a common characteristic of metastatic bone tumors?
Usually multifocal, affecting marrow-rich areas (vertebrae, pelvis, ribs, skull and sternum)
Metastatic Bone Tumors: XR
lytic, blastic or mixed lytic and blastic
Metastatic Bone Tumors secrete:
substances that promote bone resorption