bones part 2 Flashcards
Bone tumors, excluding metastatic tumors types
hematopoietic
matrix producing. Chondrogenic. Osteogenic
Unknown histologic type (10%)
fibrogenic
Misc: vascular, lipogenic, neurogenic
Bone tumors, excluding metastatic tumors facts
benign more common than malignant
most common are matrix producing (bone and cartilage) and fibrous tumors.
MOst common benign tumors are osteochondroma and fibrous cortical defect.
Most common malignant tumor are osteosarcoma > chondrosarcoma and ewings.
Bone tumors age, herditary, and associated diseases
benign tumors mostly in children/young adults; elderly is likely to be malignant
hereditary associations: Li fraumeni syndrome (p53) and heridtary retinoblastoma (Rb mutation)
other assocaitions: paget disease, metal prostehsis, chronic osteomyelitis, infarcts
Bone tumors diagnosed
benign tumors commonly present as incidnetlal finding on x ray
may present as pain as slow growing mass
may present as pathological fracture
osteoma: overview
subperiosteal or endosteal cortex surface. Common in sinuses, skull and face.
bosselated, round, oval or sessile.
woven and lamellar bone +/- marrow
incidental unless obstucting or impinging (brain or obstruct sinus.)
gradner syndrome: multiple osteomas. Intestinal polyps, epidermal cysts, and fibromatosis.
metaphysis
Osteoid osteoma
location: methaphysis cortex
bones: femur/tibia 50%/ humerus/ hands/ feet
size <2cm
Pain: intense at night
ASA/NSAID relief: yes
age: 20s
x ray: central nidus (lucency). +/- adjacent bone slcerosis and central density
histology: osteoblasts on woven bone and loose vascular connective tissue
treat: radioablation
osteoblastoma
Location: anywhere
bones: vertebrae posterior
size > 2 cm
pain dull ache
No asa or nsaid relief
age 20s
x ray radiolucent
histology osteoblasts on wven bone and loose vascular cnnective tissue
tx: excision/curretage
Osteosarcoma
most common non hematopoetic malignant primary bone tumor
by definition makes osteod
bimodal age: 75% in <20 years (50% knee). Elderly assocaited with paget’s diseass, flat and long bones, and bone infarction, prior irradiation, metal prostehsis.
painful enlarging mass
Osteosarcoma catagorized
location: medulla, cortex, periosteium
degree of differentiation
primary vs secondary
histology: amount and types of matrix
most common is primary, solitary, long bone (knee), at the metaphysis medulla, and poorly differentiated with boney matrix.
osteosarcoma: pathology
grey white with hemorrhage, necrosis
destroy adjacent bone and soft tissue
rare to breach epiphyseal plate or joint
x ray: destructive with mixed lytic and blastic. breaks through cortex. Codman triangle: tumor lifts periosteum
may have chondroid element
Osteosarcoma metastasis, survival, and genetic associations
blood born metastasis: 10-20% have lung metastasis at presentation. Lungs, bones, brain.
long term survival 60-70%
genetics: herditary retinoblastoma: RB gene defect. Li fraumeni syndrome: p53 gene defect.
osteochondroma “exostosis”
mushorrom shaped cartilage- capped. Endchondral ossification. Adolescence early adult.
metaphysis: near growth plate of long tubular bones; especially the knee
marrow and cortex continuity
multiple herediatry exostosis: autosomal dominant (double hit) and ext1 or ext 2 gene.
Osteochondroma: pathology
slow gorwing mass
pain if impinges on nerve or fracture
stop gorwing with closure of growth plate
rare risk of condrosarcoma. increased risk if multiple herediatry exostosis
chondroma: benign hylaine cartilage tumors. Two types
enchondroma: medullary cavity. Solitary in metaphysis of tubular bones. most common in hands and feet. Most common intraosseous cartilage tumor.
Subperiosteal condroma (juxtacortical chondroma): surface of bone.
age 20-50
chondroma: enchondroma. Description. associations for increased sarcoma transformation.
less than 3 cm grey blue
nodules of hyaline cartilgage with peripheral enchondral ossification.
MOst often incidental finding
rarely transform to sarcoma
increased for sarcoma transformation: enchondromatosis (ollier disease): mafucci syndrome: enchondromas with hemangiomas.
chondroma: Enchondroma xray
x ray well circumscribed lucency with a thin rim of dense bone
if calcified matrix: irregular opacities
most common bone tumor of phalynx
chondroblastoma
rare, seen in teenagers
most common in knee epiphyses
painful
x-ray: well demarcated lucency
chondroblasts
rare lung metastsis after curettage or fracture
chondrosarcoma definition and types and locations
by definition, no malignant bone formation.
classificiation by location. INtramedullary. Juxtacortical and surface
classification by histology: conventional (hyaline and/or myxoid), clear cell, dedifferentiated, mesenchymal.
Chondrosarcoma: risk factor. location. assocation
half as common as osteosarcoma
> 40 years. clear cell and mesenchymal occur teen/20s
central skeleton: pelvis, shoulder, ribs. rare to arise in distal extremities. Clear cell: long tubular bone epiphyses
15% arise in enchondroma. higher risk with multiple enchondromas and osteochondroma.
conventional chondrosarcoma diagnosis, prognosis, and metastasis
x ray: nodular growth with endosteal scalloping and flocculent densities from calcification. Reactive thickened cortex bone.
grey white glistening
malignant cartilage +/- spotty calcifications
prognosis: poor with large size and grade 3
metastasis: lungs and bone.
chondrosarcoma: types
dedifferentiated: low grade chondrosarcoma and high grade sarcoma
clear cell chondrosarcoma: teens/young adults. Epiphysis
mesenchymal chondrosarcoma: teens / young adults
firbous cortical defect non ossifying fibroma: firbous cortical defect
age: 40% children
presents: incidental
location: metaphysis/cortex knee
size: small (<0.5 cm)
course: resolve into normal bone
grey yellow brown tissue composed of fibroblasts and histiocytes
firbous cortical defect non ossifying fibroma: nonossifying fibroma
age: adolescent
presents: incidental or pathologic fracture
location: metaphysis/cortex knee
size: large up to 6 cm.
course. persists (probably prior fibrous cortical defect.
grey yellow brown tissue composed of fibroblasts and histiocytes
fibrous dysplasia: pattern. x ray and location.
three patterns: momstotic. polyostotic with soft tissue myxomas. polyostotic with endocrine dysfunction (mcCune albright syndrome)
x ray: ground glass and well demarcated border
metaphysis or diaphysis
Fibrous dysplasia monostotic
70% teens; stops growth with growth plate closure
ribs, femur, tibia, jaws, calvaria, and humerus
incidental in most cases; can be deform bone
fibrous dysplasia polyostotic
mazabraud syndrome: osft tissue myxomas
mccune albright syndrome
fibrous dysplasia: mccune albright syndrome
cafe au lait skin pigmentations
endocrine: sexual precocity (often presenting).
hyperthyrodism pituitary adenomas with GH, primary adrenal hyperplasia.
Hyper active G protein of GNAS gene.
Fibrous dysplasia: gross, microscopic description
well circumscribed intramedullary
large may expand and distort bone
gross: tan white and gritty
microscopic: chiunese character woven bone in fibrous stroma
small increased risk to become malignant: increased in polyostotic. increased if irradiated.
ewing sarcoma family: genetics. and indications in bone and soft tissue
ewing sarcoma and primitive neuroectodermal tumor (PNET): distinction based on degree of neural differentiation
80% less than 20 years. 6-10% primary bone tumors
small round (blue) cell tumor of bone and soft tissue. GLycogen. homer wright rosettes
EWS gene translocation t (11;22)( EWS-FLI1
Ewing sarcoma/Pnet: pathology. location on bone. X ray.
medullary cavity but invade the cortex into soft tissue to create a mass.
most often diaphysis of long tubular bones (femur) and flat bones of pelvis
may have fever, anemia, leukocytosis
x ray: lytic destruction with onion skin periosteal reaction and sunburst pattern
75% fiver year survival.
Giant cell tumor of bone: description, location on bone, and what part of the body most likely to affect
benign locally aggressive tumor of macrophage/monocyte system. GIant cells (can have 100+ nuclei). Mononuclear cells expressl RANKL. Hemorrhage, reactive bone, hemosiderin.
epiphyses but may extend into metaphysis
most common: knee
giant cell tumor: x ray
x ray: lytic excentric eroding into subchoroidal bone plate. May erode cortex into soft tissue with a thin shell of covering bone.
curettage: half recur.
4% metastasize to lung.
aneurysmal bone cyst (ABC): overview
mutliloculated blood-filled cysts
rapid growth may appear malignant
<20 years
metaphysis of long bones and vertebrae
most often pain and swelling
rare recurrence rate.
aneurysmal bone cyst: xray and histology
eccentric, expansile and well demarcated
histo: blood fille dcysts separated by internal septae (can see on CT or MRI)
fibroblasts and mutlinucleated giant cells.
woven bone
1/3 have cartilage like matrix (blue bone)
metastatic disease
most common form of skeletal malignancy
pathway of spread: direct extension. Lymphatic or hematogenous. Intraspinal seeding (baston plexus of veins)
may be lytic, sclerotic, or mixed.
adult metastatic disease
75% are from prostate: usually a sclerotic bone response. Breast, kidney, lung.
BLT and a kosher pickle. Breast, lung, thryoid, kidney, prostate.
most often in axial skeleton.
pediatric metastatic disease
neuroblastoma
wilms tumor
osteosarcoma
ewing sarcoma
rhabdomyosarcoma
