Patient with RTC symptoms and solitary enchondroma found on imaging. Plan?
Treat mechanical symptoms of RTCT.
No need to treat incidentally found enchondromas as they normally have nothing to do with adjacent joint mechnical symptoms
If enchondroma is truly symptomatic, then intralesional curettage
Distal radius lytic lesion DDH? (4)
Poor prognostic indicators in osteosarcoma (11)
advanced stage of disease (most predictive of survival)
response to chemotherapy (as judged by percent tumor necrosis of resected specimen)
- >98% is a good prognostic indicator, but doesn't say what's bad
tumor site and size
expression of P-glycoprotein
tumor cells can pump chemotherapy out of cell with MDR expression
present in 25% of primary lesions and 50% of metastatic lesions
high serum alkaline phosphatase
high lactic dehydrogenase
type of chemotherapy regimen
Genetic translocation association with osteosarcoma?
However it has associted mutations: p53, Rb
dDx for path with giant cells
Metastatic Tumor that is blastic?
A translocation of chromosome 11 and 22 resulting in a chimeric protein is characteristic of what Tumor?
Translocation results in EWS gene
You are working up a malignant looking tumor. It is bright on T2 with liquid, purulent looking gross pathology and no osteointegration matrix. what is it?
Synovial sarcoma treatment
Same as any other soft tissue sarcoma:
wide resection + radiation
Radiation can be pre or post op (controversial)
UNLIKE other ST sarcomas, chemo may help in synovial sarcoma in both local control and overall survival
What colour is chondroid matrix on staining?
You're suspicious of multiple myeloma. How do you stage it?
NOT bone scan, b/c they will be cold in 30% (b/c it lacks osteoblastic activity)
What is the diagnostic criteria for MM?
requires one major and one minor (or three minor) criteria for diagnosis
biopsy confirmation of plasmacytoma
>10% plasma cells on bone marrow biopsy
serum IgG > 3.5g/dL, IgA > 2g/dL
urine IgA > 1g/24hr or presence of Bence Jones proteins
10-30% plasma cells on bone marrow biopsy
serum or urine protein levels below those listed for major criteria
presence of multiple lytic bone lesions ("punched out" lesions without evidence of surrounding sclerosis)
decreased serum IgG levels
Recurrence rate of UBC
depends on treatment modality but generally up to 25-30% is reasonable
With steroids, some have reported recurrence up to 88%
What benign tumour is characterized by fatty infiltration of sub synovial connective tissue?
What primaries metastasize to bone?
Visceral carcinomas: Breast Prostate Lung Kidney Thyroid
Driving cell behind Paget's?
What primaries are most likely to present as metastasis with unknown origin?
Lung and kidney (because they are more likely to be occult)
How do you differentiate between ABC and telangiectatic osteosarcoma on MRI?
It's hard - you can't really
orthobullets says you need bx to truly differentiate
What part of bone does ewings usually occur?
Most common tumour of hand?
What on histo is pathognomonic for Schwannoma?
Composed of 2 rows of aligned nuclei in a palisading formation
Preferred treatment of EG. Name 5 modalities
Nonop with treatment of mechanical symptoms preferred
- Obervation alone
- bracing (if amenable)
- Low dose radiation (for spinal lesions that cause neuro symptoms)
- Chemo (diffuse HSC)
- Corticosteroid injections
Operative if fails:
- Curettage and bone grafting for lesions endangering articular surface
- Spinal deformity correction
Dose for adjuvant radiation in soft-tissue sarcoma?
What are complications of 45 Gy vs 60Gy?
45Gy: woudn has delayed healing
60Gy: wound not expected to heal
8 lesiosn that can be found in vertebral body
multiple myeloma (most common primary tumor of spine)
- giant cell tumor of bone: sacrum;
- eosinophilic granuloma
- osteosarcoma of the spine
- osteoid-osteoma and osteoblastoma of the spine
dDx for Benign aggressive lesion
Long term survival of parosteal osteosarcoma when local contrl has been achieved
What subtype of lipoma is painful?
Poor prognostic indicators in Ewing's
male age >14
use of radiotherapy without surgery
poor histologic response to chemo
Transcription Type II (Survival benefit with transcription type I EWS/FLI1 mutation)
Poor response to chemo
No effect of pathologic fracture
Local recurrence not as poor prognostic factor as in osteosarcoma ("death sentence" if local recurrence in osteosarcoma)
Most common site of mets of osteosarcoma
Lung: most common
Another bone: second most common