Osteosarcoma Osteomyelitis

Question 1

What is osteomyelitis?

Answer 1

commonly used term for infection in bone tissue - cortical bone and medullary cavity

Question 2

How are osteosarcoma and osetomyelitis similar?

Answer 2

both acute
both have soft tissue swelling
can have similar x-ray appearance: both cause destruction of areas of bone and bone may react with formation of new bone

Question 3

When can we suspect osteosarcoma over osteomyelitis?

Answer 3

common
older large breeds
15% groos pulmonary metastases at time of diagnosis
occurs in metaphysis (middle of bone especially long bones)
often very painful
swelling in around metaphysis
check local LN
can present with a pathological fracture: repair will fail down the line due to ongoing bone lysis

Question 4

How can we get a diagnosis for osteosarcoma?

Answer 4

FNA of bone lesion: 70% accuracy
biopsy: 80-90% accuracy
Biochem (ALP), CBC, urinalysis

Question 5

How do we stage osteosarcoma?

Answer 5

imaging of chest
bone scan or long bone survey xrays

but micrometases in 90% of cases