Bone-Forming Tumors

Question 1

Q: What is the typical age group affected by osteoid osteoma?

Answer 1

A: Teenagers and twenties.

Question 2

Q: How does the pain of osteoid osteoma present?

Answer 2

A: Localized pain, worse at night, relieved by aspirin.

Question 3

Q: Why is aspirin effective in osteoid osteoma?

Answer 3

A: Because it decreases prostaglandins (PG).

Question 4

Q: How does osteoid osteoma appear on X-ray?

Answer 4

A: Well-defined cortical metaphyseal tumor with a radiolucent central nidus.

Question 5

Q: What is seen histologically in osteoid osteoma?

Answer 5

A: Interlacing trabeculae of woven bone surrounded by osteoblasts with a central vascularized nidus.

Question 6

Q: What are the two types of osteomas?

Answer 6

A: Simple osteoma and multiple osteomas.

Question 7

Q: Where do simple osteomas typically occur?

Answer 7

A: In bones of the skull.

Question 8

Q: What syndrome is associated with multiple osteomas?

Answer 8

A: Gardner syndrome (APC mutation).

Question 9

Q: What cancer is associated with Gardner syndrome?

Answer 9

A: Early development of colon cancer.

Question 10

Q: How is osteoblastoma different from osteoid osteoma in size?

Answer 10

A: Osteoblastoma is larger than 1.5–2 cm.

Question 11

Q: Where is osteoblastoma more commonly located?

Answer 11

A: In the axial skeleton (vertebrae).

Question 12

Q: How does the pain in osteoblastoma differ from osteoid osteoma?

Answer 12

A: Pain is less localized and not responsive to aspirin.

Question 13

Q: How does osteoblastoma grow?

Answer 13

A: Slowly growing but may progress and increase in size (aggressive osteoblastoma).

Question 14

What type of matrix do neoplastic cells produce in osteosarcoma?

Answer 14

Osteoid matrix.

Question 15

What is the most common primary malignant non-hematopoietic bone tumor?

Answer 15

Osteosarcoma.

Question 16

What is the male-to-female ratio in osteosarcoma?

Answer 16

Males more than females.

Question 17

At what age does osteosarcoma most commonly occur?

Answer 17

75% occur under 20 years old.

Question 18

Where in the bone does osteosarcoma usually arise?

Answer 18

Metaphyses of long bones, mostly around the knee.

Question 19

What genetic syndrome is associated with multiple osteosarcomas in children?

Answer 19

Li-Fraumeni Syndrome (p53 mutation).

Question 20

What are secondary causes of osteosarcoma?

Answer 20

Paget disease, irradiation, osteomyelitis.

Question 21

What is the usual path of tumor growth in osteosarcoma?

Answer 21

Intramedullary → cortex → periosteum → soft tissue.

Question 22

What are the three locations/types of osteosarcoma based on position?

Answer 22

Intramedullary (high grade), Paraosteal (low grade), Periosteal (intermediate-high grade).

Question 23

What genetic mutation is found in 60-70% of sporadic osteosarcoma cases?

Answer 23

RB gene mutation on chromosome 13.

Question 24

Which inherited condition dramatically increases the risk of osteosarcoma?

Answer 24

Familial retinoblastoma.

Question 25

What are the common clinical features of osteosarcoma?

Answer 25

Enlarging mass, with or without pain.

Question 26

Where does osteosarcoma commonly metastasize?

Answer 26

Lungs (hematogenous spread).

Question 27

What is a classic X-ray finding in osteosarcoma?

Answer 27

Codman's triangle (periosteal reaction with new bone formation).

Question 28

What are key pathological features seen in osteosarcoma histology?

Answer 28

Pleomorphic large malignant cells, prominent mitoses, numerous osteoclasts, lace-like osteoid.

Question 29

What are the histological variants of osteosarcoma?

Answer 29

Osteoblastic, chondroblastic, fibroblastic, telangiectatic, and others.

Question 30

What is the sequence of osteosarcoma treatment?

Answer 30

Chemotherapy before surgery → assess necrosis → surgery → radiation if needed.

Question 31

What does the prognosis of osteosarcoma mainly depend on?

Answer 31

Stage, variant of the tumor, and location (stage more important than grade).