osteoarticular 3

Question 1

What is the location of chondrosarcoma

Answer 1

Shoulder, spine, pelvis etc

clear cell varient of chondrosarcoma occurs in epiphysis of tubular long bone

Question 2

3 types of chondrosarcoma

Answer 2

1. Clear cell chondrosarcoma
2. Differentiated chondrosarcoma
3. Mesenchymal chondrosarcoma

Question 3

Loc of Fibrous cortical defect

Answer 3

Metaphysis of distal femul or prox tib

Question 4

types of fibrous dysplasia and %

Answer 4

Monostotic- 70% of cases

Polyostotic- 27%

Question 5

Mutation in fibrous dysplasia

Answer 5

Gene for g pro leading to activation and excessive prod of cAMP

Question 6

What is mcCune albright syndrome

Answer 6

polyostotic w cafe au lait spots

Question 7

Age of giant cell tumor and what is it characterized histolocially

Answer 7

20-40

characterized by presence of multinucleated giant cells

Question 8

loc of giant cell tumor of the bone in adults + adolescents

Answer 8

Adults- epiphysis or metaphysis of long bones

adolescents- metaphysis

Question 9

s/s of ewing sarcoma

Answer 9

• localied pain (back pain)
• palpable mass
• systemic symptoms

Question 10

95% of ewing sarcomas have one of these translocatuons

Answer 10

translocation of t(11;22), t(21;22)

-fusion of EWS to FLI or ERG

Question 11

microscopic findings in Ewing sarcoma (3)

Answer 11

• small round cell tumor
• positive for CD 99
• Forms Homer-wright rosettes