422 - 423 - Primary Bone Tumors Flashcards
What are 2 benign bone tumors?
- Giant cell tumor
2. Osteochondroma (exostosis)
Patients in what age range get giant cell tumors?
20 - 40 years old
In what part of the bone do giant cell tumors typically arise?
epiphyseal end of long bones (especially distal femor or proximal tibia, i.e. near the knee)
A locally aggressive benign tumor that often occurs around the knee:
giant cell tumor
How do giant cell tumors appear on x-ray?
soap bubble appearance
How do giant cell tumors appear on histology?
multinucleated giant cells
What is the most common benign tumor of the bone?
osteochondroma
What demographic does osteochondroma affect?
Males < 25 years old
What would you see on histology of an osteochondroma?
Mature bone with a cartilaginous cap
Does osteochondroma transfrom to chondrosarcoma?
Rarely
What are 3 examples of malignant bone tumors?
- Osteosarcoma (osteogenic sarcoma)
- Ewing sarcoma
- Chondrosarcoma
After multiple myeloma, what is the second most common primary malignant bone tumor?
osteosarcoma
What age demographic does osteosarcoma affect?
Bimodal distribution: 10-20 y.o. (primary) and > 65 y.o. (secondary)
What are 5 predisposing factors of osteosarcoma?
- Paget disease of the bone
- Bone infarcts
- Radiation
- Familial retinoblastoma,
- Li-Fraumeni syndrome (germline P53 mutation)
What part of the bone is affected by osteosarcoma?
Metaphysis of long bones, often around the knee
How do osteosarcomas appear on x-ray?
Codman triangle or sunburst pattern
What creates the Codman triangle pattern on x-ray of an osteosarcoma?
elevation of the periosteum
Are osteosarcomas slow growing or aggressive?
aggressive
How do you treat osteosarcoma?
Surgical en bloc resection (with limb salvage) and chemotherapy
Who gets Ewing sarcomas?
Boys < 15 years old
Where does Ewing sarcoma appear in the body?
diaphysis of long bones, pelvis, scapula, and ribs
How do Ewing sarcomas appear on histology?
Anaplastic small blue cells (that arise from neuroectoderm)
What is the course of Ewing sarcoma?
Extremely aggressive with early metastases, but responsive to chemotherapy
Which tumor is associated with an onion skin appearance of the bone?
Ewing sarcoma
What is the translocation in Ewing sarcoma?
t(11;22)
11 + 22 = 33 (Patrick Ewing’s jersey number)
Who gets chondrosarcomas?
Men 30-60 years old
Where do chondrosarcomas appear?
Usually in the pelvis, spine, scapula, humerus, tibia, or femur
Are chondrosarcomas common?
No, rare
What are 2 ways chondrosarcomas can arise?
- Primary
2. Transformation of osteochondroma
What do chondrosarcomas look like grossly?
expansile glistening mass within the medullary cavity
What is an exostosis? What kind of bone tumor is associated with exostosis?
Projection of new bone out of the surface of a bone (continuous with bone marrow), associated with osteochondroma (arises as a lateral projection of the growth plate)
What is an osteoid osteoma? Where does it arise? (pathoma)
A benign tumor of osteoblasts surrounded by a rim of reactive bone; cortex of long bone (diaphysis)
Who gets osteoid osteomas?
Adults <25 y.o.
What does an x-ray of osteoid osteoma show?
Bony mass with radiolucent (osteoid) core
What is an osteoma? What disease are they associated with?
A benign bone tumor that usually occurs in the skull. They commonly arise in the surface of facial bones in patients with Gardner syndrome
Where do chondromas typically arise?
in the medulla of small bones of hands and feet
Are primary or metastatic tumors in the bone more common?
metastatic
