Components of local staging?
MRI to characterize lesion (of entire bone)
Biopsy (can do soft tissue mass)
Send for pathology and cultures
Good lesional tissue
Use pathology to prognosticate
Physical exam for metastasis with unknown origin must include?
Describe the bones in enchondromatosis?
They are not normal and can have deformities
Young, thirsty kid with these findings.
Hans-Schuller-Christian disease (disseminated eosinophilic granuloma)
Lytic skull lesions
What malignant tumour can secondarily arise from a bone infarct, Paget's disease or prior radiation?
Malignant fibrous histiocytoma
(aka Undifferentiated pleomorphic sarcoma)
What do you do following unplanned excision of soft tissue sarcoma?
Work up as normal
Local staging to look for extent of tumour bed and contamination
Systemic staging to look for mets
Definitive is re-resection of tumour bed and all associated contaminated compartments
Radiotherapy (controversial whether pre or post-op)
Tumour association with poly-vinyl chloride
very aggressive vascular tumour
Overall prognosis for multiple myeloma?
What confers the worst prognosis?
Median survival 3 years from diagnosis
5 year survival: 30%
10 years survival: 10%
Shortest survival in patients with renal failure
Name 3 syndromes assocaited with Fibrous Dysplasia
What sarcoma has flat epithelial cells on pathology?
What is radiation dose for HO prophylaxis?
(vs. 45-60 for soft tissue sarcoma)
Genetics for myxoid liposarcoma
Creates CHOP-TLS fusion protein
What physeal zone does osteochondroma/MHE stem from?
What Tumor stains for MIC2 antigen?
This is how you differentiate it from other small round blue cell tumors.
What is the most common malignant bone tumour of the hand?
THINK: common to have enchondromas in hand, so one of them must transform
3 non-neoplastic things to consider adding on to the end of a ddx for bone lesion?
Hyperparathyroidism (if older)
What is the recurrence rate of osteoid osteoma treated with percutaneous radiogrequency ablation?
Describe Harington's Criteria
>50% destruction of diaphyseal cortices
>50-75% destruction of metaphysis (>2.5cm)
Permeative destruction of the subtrochanteric fermoal region
persistent pain following irradiation
Treatment of osteofibrous dysplasia?
nonoperative - observation
bracing if deformity interfering with walking
OR if you need correction of deformity (osteotomy)
Cause of Paget's
Thought to be a slow viral infection by paramyxovirus or RSV as most are spontaneous
There is a small group of heritable Paget's also
What kind of matrix does ewings usually have?
Poor prognostic indicators for EG
involvement at young age
rapid disease progression
organ involvement (eg pituitary, lung, hematopoietic, or liver involvement);
*organ dysfunction carries an especially poor prognosis
Older than 40 , blastic lesion DDx (4)?
Name two enchondroma syndromes.
Classic findings of Hans-Christian-Schuller Disease
Disseminated form of EG
diabetes insipidus (thirst)
Exopthalmos (double vision)
Osteolysis in tumour is caused by the action of what cytokine on what cell?
RANKL on osteoclastic cells (not on tumour cells)
Genetically, how does osteofibrous dysplasia differ than regular fibrous dysplasia?
It doesn't have the Gs alpha activating mutation
Name the basic biopsy principles.
1. Biopsy through (single) involved compartment
2. Use extensile incision (usually longitudinal)
3. Meticulous hemostasis
4. Do not create multiple planes
5. Bring out drains in line with incision (so the tunnel can be removed with definitive resection)
6. should biopsy soft tissue component of bone tumour if possible
7. round holes in bone, not square
8. do not exanguinate before tourniquet
9. avoid nv structures
Compare pre vs. post operative radiation for soft tissue sarcoma:
Lower field (b/c you haven't contaminated it with surgery)
Lower rates of fibrosis
Also lower rates of edema and joint stiffness, but not statistically significant (Lower overall functional rates if they had fibrosis, edema and stiffness)
HOWEVER: higher risk of wound infection
Generally, neoadjuvant (pre) RTx is better, even tho wound complications are higher
SR2 study: know this data - it's canadian
6 lesions on the posterior elements of spine
G: giant cell tumour (although most commonly in vertebral body)
A: aneurysmal bone cyst (only one PURELY found posteriorly)
P: Paget disease
E: eosinophilic granuloma