What percentage response to chemo is a good prognostic indicator?
Where do neurofibrosarcoma's arise?
From a peripheral nerve or from a neurofibroma (malignant transformation)
What must you do to gain adequate margins when resecting a chordoma?
Sacrifice the nerve roots
You suspect soft tissue sarcoma but MRI is indeterminant.
Your core biopsy comes back as hematoma only
CANNOT resect this tumour if you suspect soft tissue sarcoma as many of the core's come back as hematoma
Recurrence of chondrosarcoma is directly related to what?
Increased telomerase activity
In synovial chondromatsis, is the cartilage normal?
No - metaplastic
Benign bone lesion in spine is usually what?
Does radiation have a role in treatment of Ewing's sarcoma?
Yes, if wide resection is technically difficult or if a Tumor was inadequatly resected based on pathology
Synovial sarcoma is a misnomer. What percentage of these tumours actually arise is a major joint?
At what age does metastases become more common than primary bone malignancy?
epiphyseal crossing into metaphysis
lots of surrounding edema
dDx: clear cell chondrosarc
How can you differentiate schwannoma from neurofibroma on MRI?
Schwannoma is eccentric and separate from nerve.
Neurofibroma is central with the nerve runnign through it.
What is the most important factor in preventing local recurrence of a tumour?
adequacy of surgical margin
Treatmet for symptomatic, large NOFs
curettage & bone graft
This patient is having leg pain unresponsive to conservative mangaement.
Treatment with metaphyseal osteotomy with plate fixation
(Metaphyseal > diaphyseal, plate > IMN - Parvizi)
3 Manifestations of fibrous dysplasia
Treatment of lymphoma
Multiagent chemotherapy ± local radiation
± surgical fixation for instability/pathologic fractures
Accuracy of core biopsy done in the office?
What is the classification system for GCT?
I: Intramedullary lesion confined to bone
II: Thinned, expanded lesion
III: Cortical breach
Name 3 reasons why prophylactic fixation is better than fixing an actual pathologic fracture
Shorter OR time
You diagnose myxoid liposarcoma. How do you stage?
CT chest, abdo, pelvis
(not just CT chest)
Myxoid liposarcoma specifically has the tendency to spread to areas other than lungs
2 differentiating factors from myositis ossificans and tumour
Calcifies from outside - in (vs. tumour - inside out)
What Tumor has characteristic fluid levels on MRI?
Most common site for bony mets
Most common site for pathologic fracture secondary to mets to bone
Most common site: thoracic spine
Most common site of pathologic fracture due to mets: proximal femur
Treatment algorithm for soft tissue sarcoma
Radiation + wide excision
Whether you do pre-vs. post op radiation is controversial with pros and cons
Risk of metasteses with Liposarcoma by grade?
- Low grade (well differentiated) =
- High (undifferentiated) = 50%
Cell type of synovial sarcoma
Usually biphasic with spindle cells (fibrous) & epithelial cells
NOT SYNOVIAL CELLS
Lifetime risk of malignant transformation for multiple hereditory exostosis?
Name the radio-resistant tumours
Undifferentiated soft tissue tumour & chondrosarcoma (Except mesenchymal and dedifferentiated??)
What is the most common solid tumour of childhood?
Is it malignant or benign?