bones part 2

Question 1

Bone tumors, excluding metastatic tumors types

Answer 1

hematopoietic

matrix producing. Chondrogenic. Osteogenic

Unknown histologic type (10%)

fibrogenic

Misc: vascular, lipogenic, neurogenic

Question 2

Bone tumors, excluding metastatic tumors facts

Answer 2

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.

Question 3

Bone tumors age, herditary, and associated diseases

Answer 3

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

Question 4

Bone tumors diagnosed

Answer 4

benign tumors commonly present as incidnetlal finding on x ray

may present as pain as slow growing mass

may present as pathological fracture

Question 5

osteoma: overview

Answer 5

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

Question 6

Osteoid osteoma

Answer 6

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

Question 7

osteoblastoma

Answer 7

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

Question 8

Osteosarcoma

Answer 8

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

Question 9

Osteosarcoma catagorized

Answer 9

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.

Question 10

osteosarcoma: pathology

Answer 10

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

Question 11

Osteosarcoma metastasis, survival, and genetic associations

Answer 11

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.

Question 12

osteochondroma “exostosis”

Answer 12

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.

Question 13

Osteochondroma: pathology

Answer 13

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

Question 14

chondroma: benign hylaine cartilage tumors. Two types

Answer 14

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

Question 15

chondroma: enchondroma. Description. associations for increased sarcoma transformation.

Answer 15

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.

Question 16

chondroma: Enchondroma xray

Answer 16

x ray well circumscribed lucency with a thin rim of dense bone

if calcified matrix: irregular opacities

most common bone tumor of phalynx

Question 17

chondroblastoma

Answer 17

rare, seen in teenagers

most common in knee epiphyses
painful

x-ray: well demarcated lucency

chondroblasts

rare lung metastsis after curettage or fracture

Question 18

chondrosarcoma definition and types and locations

Answer 18

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.

Question 19

Chondrosarcoma: risk factor. location. assocation

Answer 19

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.

Question 20

conventional chondrosarcoma diagnosis, prognosis, and metastasis

Answer 20

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.

Question 21

chondrosarcoma: types

Answer 21

dedifferentiated: low grade chondrosarcoma and high grade sarcoma

clear cell chondrosarcoma: teens/young adults. Epiphysis

mesenchymal chondrosarcoma: teens / young adults

Question 22

firbous cortical defect non ossifying fibroma: firbous cortical defect

Answer 22

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

Question 23

firbous cortical defect non ossifying fibroma: nonossifying fibroma

Answer 23

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

Question 24

fibrous dysplasia: pattern. x ray and location.

Answer 24

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

Question 25

Fibrous dysplasia monostotic

Answer 25

70% teens; stops growth with growth plate closure

ribs, femur, tibia, jaws, calvaria, and humerus

incidental in most cases; can be deform bone

Question 26

fibrous dysplasia polyostotic

Answer 26

mazabraud syndrome: osft tissue myxomas

mccune albright syndrome

Question 27

fibrous dysplasia: mccune albright syndrome

Answer 27

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.

Question 28

Fibrous dysplasia: gross, microscopic description

Answer 28

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.

Question 29

ewing sarcoma family: genetics. and indications in bone and soft tissue

Answer 29

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

Question 30

Ewing sarcoma/Pnet: pathology. location on bone. X ray.

Answer 30

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.

Question 31

Giant cell tumor of bone: description, location on bone, and what part of the body most likely to affect

Answer 31

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

Question 32

giant cell tumor: x ray

Answer 32

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.

Question 33

aneurysmal bone cyst (ABC): overview

Answer 33

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.

Question 34

aneurysmal bone cyst: xray and histology

Answer 34

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)

Question 35

metastatic disease

Answer 35

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.

Question 36

adult metastatic disease

Answer 36

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.

Question 37

pediatric metastatic disease

Answer 37

neuroblastoma

wilms tumor

osteosarcoma

ewing sarcoma

rhabdomyosarcoma