Bone tumors

Question 1

What are the risk factors for osteoid osteoma?

Answer 1

Young adults, males

Question 2

Where are the most common sites for osteoid osteomas?

Answer 2

Appendicular skeleton; diaphysis and metaphysis of distal humerus, digits of the hand, femur, tibia

Question 3

What are the three primary characteristics of osteoid osteomas?

Answer 3

Small size, self-limiting growth, tendency to cause extensive reactive changes in adjacent tissues

Question 4

What size are osteoid osteomas?

Answer 4

Usually 1cm or less

Question 5

What are the radiological features of osteoid osteomas?

Answer 5

Nidus with sclerotic reaction, cortical thickening

Question 6

What are the histological features of osteoid osteomas?

Answer 6

Irregular bone trabeculae lined by benign osteoblasts, fibrovascular stroma, occasional osteoclasts, sclerotic surrounding bone

Question 7

What is the typical clinical presentation of osteoid osteoma?

Answer 7

Nocturnal pain alleviated by NSAIDs

Question 8

What is the typical clinical presentation of osteoblastoma?

Answer 8

Dull/achy pain, may be relieved by NSAIDs

Question 9

What are the risk factors for osteoblastoma?

Answer 9

Young adults, male

Question 10

What are the most common sites for osteoblastoma?

Answer 10

Axial/spine, diaphysis and metaphysis of lower extremity

Question 11

What are the risk factors for osteosarcoma?

Answer 11

Children/young adults, elderly, Paget disease, familial retinoblastoma, LiFraumeni syndrome (germline p53 mutation)

Question 12

Is osteoid osteoma benign or malignant?

Answer 12

Benign

Question 13

Is osteoblastoma benign or malignant?

Answer 13

Benign

Question 14

What are the radiological findings of osteoblastoma?

Answer 14

Lytic with or without sclerotic margin; internal calcification and ossification; lacks surrounding bone sclerosis

Question 15

What are the histological findings of osteoblastoma?

Answer 15

Similar to osteoid osteoma without surrounding bone sclerosis; irregular bone trabeculae lined by benign osteoblasts, associated fibrovascular stroma and occasional osteoclasts

Question 16

Is osteosarcoma benign or malignant?

Answer 16

Malignant

Question 17

Where are tumors usually located in osteosarcoma?

Answer 17

Metaphysial (long bones) in youth, often distal femur or proximal tibia; axial skeleton/flat bones in older adults

Question 18

What are the typical radiological findings in osteosarcoma?

Answer 18

Lytic and/or sclerotic appearance; Codman triangle (elevation of periosteum) or sunburst pattern

Question 19

What are the typical histological findings in osteosarcoma?

Answer 19

Atypical malignant cells producing osteoid of mineralized neoplastic bone, usually accompanied by mitotic activity and necrosis, host bone permeation

Question 20

What are the two genes that are often involved in low grade osteosarcoma?

Answer 20

CDK4 and MDM2

Question 21

What are the risk factors for osteochondroma?

Answer 21

Young adults, male

Question 22

Is osteochondroma benign or malignant?

Answer 22

Benign

Question 23

Where are tumors usually found in osteochondroma?

Answer 23

Usually metaphysis of long bones that undergo endochondral ossification

Question 24

What genes are often involved in osteochondroma?

Answer 24

EXT1 and EXT2

Question 25

What are the typical radiological features of osteochondroma?

Answer 25

Bony exostosis with cartilaginous cap (First Aid); pedunculated or sessile ossified stalk in communication with underlying bone that grows away from adjacent joint (lecture)

Question 26

What are the typical histological findings of osteochondroma?

Answer 26

Hyaline cartilage cap undergoing endochondral ossification to bone with normal marrow

Question 27

Where in the body are tumors usually found in enchondroma?

Answer 27

Appendicular skeleton, usually hands and feet

Question 28

What are the typical radiological findings in enchondroma?

Answer 28

Circumcised lytic lesions, usually with punctate and ring-like calcifications

Question 29

What are the typical histological findings in enchondroma?

Answer 29

Nodular growth of hyaline cartilage in medullary region or surface of bone

Question 30

What genes are often involved in enchondroma?

Answer 30

IDH1 and IDH2

Question 31

What are the risk factors for chondrosarcoma?

Answer 31

Older adults

Question 32

Where in the body are tumors usually found in chondrosarcoma?

Answer 32

Axial skeleton; pelvis, humerus, proximal femur

Question 33

What are the typical radiological findings in chondrosarcoma?

Answer 33

Lytic, destructive lesion usually with punctate and ring-like calcification

Question 34

Is chondrosarcoma benign or malignant?

Answer 34

Malignant

Question 35

Is enchondroma benign or malignant?

Answer 35

Benign; may progress to chondrosarcoma

Question 36

What are the typical histological findings in chondrosarcoma?

Answer 36

Bone invasion and entrapment with possible necrosis; abnormal matrix-producing cartilage

Question 37

What are the risk factors for giant cell tumor of bone?

Answer 37

Age 20-40 years, skeletally mature

Question 38

Are giant cell tumors benign or malignant?

Answer 38

Benign; locally aggressive

Question 39

What are the typical radiological findings in giant cell tumors?

Answer 39

Lytic lesion involving epiphysis; soap bubble-like appearance

Question 40

Where are giant cell tumors usually found?

Answer 40

Epiphysis of long bones, usually distal femur and proximal tibia

Question 41

What are the typical histologic findings in giant cell tumors?

Answer 41

Sheets of osteoclastic giant cells with numerous nuclei

Question 42

What are the risk factors for Ewing sarcoma?

Answer 42

Age <20, male

Question 43

Where are tumors usually found in Ewing sarcoma?

Answer 43

Diaphysis of long bones; pelvis, scapula, ribs

Question 44

What is the genetic mutation associated with Ewing sarcoma?

Answer 44

t(11;22) causing EWSR1-FLI1 fusion gene

Question 45

What are the typical radiologic features of Ewing sarcoma?

Answer 45

Destructive and permeative tumor, usually in diaphysis, often soft tissue extension; onion skin periosteal reaction

Question 46

What are the typical histological findings in Ewing sarcoma?

Answer 46

Anaplastic small "blue cells" (small, round, little cytoplasm, fairly uniform in size and shape), possible necrosis