PATH - Primary Bone Tumors

Question 1

Osteochondroma

Answer 1

Most common *benign bone tumor.

Bony exostosis with cartilaginous (chondroid) cap

Males

Question 2

Giant cell tumor

Answer 2

Locally aggressive *benign tumor.

Epiphyseal end of long bones. Often around knee.

“Soap bubble” appearance on x-ray
Multinucleated giant cells

“Osteoclastoma.”

20–40 years old.

Question 3

Osteosarcoma

osteogenic sarcoma

Answer 3

2nd most common 1° *malignant bone tumor (after multiple myeloma).

Metaphysis of long bones, often around knee

Codman triangle (from elevation of periosteum)
or sunburst pattern on x-ray.

Bimodal distribution: 10–20 yo (1°), > 65 (2°).

Question 4

Ewing sarcoma

Answer 4

Anaplastic small *blue cell *malignant tumor

Commonly appears in diaphysis of long bones, pelvis, scapula, ribs

“Onion skin” periosteal reaction in bone

Associated with *t(11;22) translocation causing fusion protein *EWS-FLI 1.
11 + 22 = 33 (Patrick Ewing’s jersey number).

Extremely aggressive with early metastases, but responsive to chemotherapy

Boys