Chondroblastoma, infection, GCT
Does thickness of cartilage cap have an associated with risk of sarcomatous change in osteochondroma?
If so, what is the limit?
Yes, but only in adults (skeletally mature)
In kids, it is an unreliable finding
>2cm is a risk for change to chondrosarcoma
What is the main dDx for intramuscular myxoma that you must rule out?
True or false, lipomas can present with pain?
Angiolipoma often present as a painful mass
Name some negative prognostic characteristics of osteosarcoma.
1. Poor response to Neo adjuvant chemo (% necrosis)
2. Tumour size (> 8 cm is bad)
3. Patient age (old is bad)
4. Higher stage of Tumor
5. Anatomical site (central is bad)
dDx for soft tissue sarcoma?
±HO/MO if within a muscle
Chrondroblastomas are located where?
Lifetime risk of malignant transformation for olliers?
What are characteristics of a metastasis on X-ray?
Proximal long bone or spine
Describe the Enneking system for classifying malignant tumours.
Three factors: Grade, site and metasteses
Grade is high or low
Site is intracompartmental (enclosed by natural barriers) or extracompartmental
Parosteal osteosarcoma with invasion into medullary cavity - what is the affect on prognosis?
No effect - still good prognosis
Name 2 scoring systems that may help you decide whether to operate on a pathologic spine tumour
Spinal instability neoplastic score
based on: location, pain, type of lesion, spinal alignment, vertebra body collapse, involvement of posterior elements
7-12: impending instability
Modified Tokohashi Scoring system
based on: Karnofsky performance status, # of extraspinal bony mets, # of vertebral body mets, Mets to major organs, primary site of cancer, palsy
0-8: <6 months life expecancy: conservative + palliative
9-11: life expectancy > 6 months: palliative surgery
12-15: life expectancy > 1 year. Excisional surgery
I think the principles of these scoring systems are imporant
Dx & Treatment?
These are usually low grade
Treat with Wide-resection only (usually curative)
Chemo generally not indicated unless there is a high grade component
Presentation of glomus Tumour
- cold sensitivity
- point tenderness
- intermittent severe pain
Also may have a bluish-reddish hue
Occur in subungal region
X-rays will show a scalloped, osteolytic defect
Name the 5 subtypes of liposarcoma.
Well differentiated liposarcoma
What is the most common sarcoma in the foot?
Soft tissue tumours that mets via LN & to places other than lungs
Clear cell sarcoma
Name 2 sarcomas for which excisional bx can be performed
low grade chondrosarcoma
*not sure I would say this on an exam
It's from AAOS CORE2
What is a defining feature on histo for extra-articular desmoid tumour?
100% positive for estrogen receptor-beta
4 Options for treating PVNS (think techniques)
Arthroscopic synovectomy: best for focal disease
arthroscopic + open synovectomy (ie arthroscopic + open posterior knee approach)
Total joint arthroplasty + synovectomy
Total synovectomy + arthrodesis
± radiation - addition of radiation combined with total synovetomy reduces recurrence to 10-20%
Risks for post-radiation fracture
Anterior femoral compartment resection
2 negative prognostic indicators of CMF
lobulated with abundant myxoid material
Football player suffered injury after helmet to groin hit. Residual non-tender mass.
Non-operative - most resolve in a year or so
If recalcitrant, excise, but not before it matures (> 6 months)
Note x-ray: it calcifies from outside in, vs. tumour, which goes inside out
Olliers is characterized by:
A) multiple enchondromas, hemangiomas, lymphangiomas
B) multiple enchondromas in a unilateral distribution
C) auto-dominant transmission, multiple enchondromas and osteochondromas
What colour is bone matrix on staining?
What findings differentiate chondrosarcoma from a benign lesion?
1) myxoid matrix - may still have chondroid matrix, but generally the more myxoid the higher the grade
2) cortical thinning or thickening
3) soft tissue mass
4) invasion of haversian system
5 tumors that can have an associated ABC?
- giant cell tumor
- fibrous dysplasia
- chondromyxoid fibroma
Fallen leaf sign
what is it
what is it pathognomonic for?
Cortical fragment in the bottom of an empty cyst
4 associated conditions of NOF
Familial multifocal NOF
What is the treamtnet of low-grade intramedullary osteosarcoma?
Surgial resection only
This is the exception of the usual rule of chemo-sx-chemo for sarcoma