Bone Tumors

Question 1

Prominent osteoblasts w/ rim of reactive cortical bone

Answer 1

Osteoid osteoma + osteoblastoma

Question 2

Symptoms of chondrosarcoma

Answer 2

Painful, progressively enlarging mass

Question 3

Location of involvement of osteochondromas

Answer 3

Metaphysis of long tubular bones esp. near knee

Question 4

Location of giant cell tumor involvement

Answer 4

Epiphysis of long bones

Question 5

Osteolytic bone metastasis

Answer 5

Breast, kidney, lung mets

Question 6

Associated w/ Gardner syndrome

Answer 6

Osteoma

Gardner syndrome= FAP + osteoma + fibromatosis of retroperitoneum

Question 7

Benign bone forming tumors (3)

Answer 7

1) Osteoma
2) Osteoid osteoma
3) Osteoblastoma

Question 8

Malignant proliferation of poorly differentiated cells derived from neuroectoderm

Answer 8

Ewing sarcoma

Question 9

Difference between osteochondroma + hereditary multiple exostosis

Answer 9

Multiple herediatry exostosis has significantly increased risk for chondrosarcoma

Question 10

Imaging findings for osteoid osteoma + osteoblastoma

Answer 10

Radiodense bony mass w/ lucent core (osteoid) within cortex

Question 11

Risk factors/ epidemiology of primary osteosarcoma

Answer 11

Risk factors: Li-Fraumeni syndrome, Familial retinoblastoma, radiation

Epidemiology: Teenagers

Question 12

Osteoblastic metastasis

Answer 12

From prostate CA

Question 13

Histology: Disorganized cartilage in growth plate

Answer 13

Osteochondroma

Question 14

Risk factors/ epidemiology of secondary osteosarcoma

Answer 14

1) Radiation
2) Paget disease
3) Bone infarcts

Question 15

Malignant proliferation of osteoblasts

Answer 15

Osteosarcoma

Question 16

Benign cartilage forming tumors (2)

Answer 16

1) Osteochondroma (& multiple hereditary exostosis- increased risk for chondrosarcoma)
2) Echondroma (& multiple echondroma disorders- increased risk for chondrosarcoma)

Question 17

Histology of Ewing sarcoma

Answer 17

Small, round blue cells resembling lymphocytes (can be misdiagnosed as lymphoma)

Homer Wright rosettes

Question 18

Location of involvement of echondroma

Answer 18

Medullary cavity of small bones (hands + feet)

Question 19

Location of involvement of secondary osteosarcoma

Answer 19

Femur, pelvis, humerus

Question 20

Etiology of Ewing sarcoma

Answer 20

t(11;22) –> fusion protein EWS-FLI1

Question 21

Location of involvement of Ewing sarcoma

Answer 21

Diaphysis of long bones

Question 22

Tumor of osteoblasts that make large amounts of RANKL, stimulating osteoclasts to grow

Answer 22

Giant cell tumor

Question 23

Location of involvement of osteoid osteoma

Answer 23

Diaphysis of long bones (e.g. femur) within cortex

Question 24

Two diseases that appear same on imaging

Answer 24

Echondroma + chondrosarcoma- both appear lucent w/ internal mineralization

Question 25

Location of chondrosarcoma involvement

Answer 25

Medulla of pelvis or axial skeleton (shoulder, pelvis, proximal femur, ribs)

Question 26

Multiple echondroma disorders (2)

Answer 26

Ollier disease, Maffuci syndrome; associated w/ multiple sites of echondromas; increased risk of chondrosarcoma

Question 27

Histology of osteosarcoma (primary and secondary)

Answer 27

Malignant osteoblasts forming osteoid (disorganized pink matrix)

Question 28

Bone pain that resolves w/ ASA

Answer 28

Osteoid osteoma

Question 29

Location of involvement of primary osteosarcoma

Answer 29

Metaphysis of long bones, usually around the knee (distal femur, proximal tibia)

Question 30

Histology of giant cell tumors

Answer 30

multinucleated giant cells that express RANKL

Question 31

Symptoms of Ewing sarcoma

Answer 31

Painful, enlarging mass that's frequently tender, warm, swollen Systemic findings: fever, anemia, leukocytosis

Question 32

Histology of osteoid osteoma

Answer 32

Woven bone w/ prominent osteoblasts + rim of reactive cortical bone

Question 33

Differences between osteoid osteoma + osteoblastoma (3)

Answer 33

1) Location of involvement: osteoid osteoma involves diaphysis of long bones while osteoblastoma involves vertebrae. 2) Size- osteoid osteoma is less than 2 cm; osteoblastoma is larger than 2 cm 3) Aspirin- osteoid osteoma bone pain resolves with ASA; osteoblastoma bone pain doesn't resolve w/ ASA

Question 34

Common location of osteomas

Answer 34

Facial bones/ skull

Question 35

Symptoms of osteosarcoma

Answer 35

Bone pain, pathologic fractures. No systemic sx.

Question 36

"Sunburst" appearance + Codman's triange (lifting of periosteum) on imaging

Answer 36

Osteosarcoma (primary and secondary)

Question 37

Malignant cartilage forming tumor

Answer 37

Chondrosarcoma

Question 38

Cartilage-capped tumor attached by bony stalk (exostosis) to underlying skeleton

Answer 38

Osteochondroma

Question 39

Benign tumor of hyaline cartilage

Answer 39

Echondroma

Question 40

Soap bubble appearance on x-ray

Answer 40

Giant cell tumor

Question 41

Location of giant cell tumor involvement

Answer 41

Epiphysis of long bones, usually region of knee (distal femur/ proximal tibia)

Question 42

Histology of echondroma

Answer 42

Nodular hyaline cartilage w/ overlying rim of reactive bone