Unit 23 Flashcards
why is secondary bone ca (BCA) common
because of inc vascularity of bone -> inc blood moves here -> inc probablity of emboli to move thru bone
where does most bone growth occur
metaphysis
what does bone form from
cartildige
why is identification of primary bca hard
diverse types
what do we identify bone ca based on
histology
location of ca in skeleton and in bone itself
what type of tumor is osteosarcoma
bone forming
how common is osteosarcoma
most common
where does osteosarcoma usually originate (skeleton)
around knee
characteristics of mets in osteosarcoma
quick and easy, to lung
what pts does 75% of osteosarcoma occur in
pts under 20
why does most osteosarcoma occur in young pts
dt inc cell prolif/dna replication that occurs prior to the halt of longitudinal bone growth at age 20. inc cell prolif-> inc risk of gene mutation
what pts does 25 % of osteosarcoma occur in
geri pts with underlying pathologic bone disease eg pagets
why does 25% of osteosarcoma occur in geri puts
pts with bone diseaes have inc resoprtion and formation of bone, this means there is still cell prolif/dna replication -> risk for gene mutatin
other primary malignancies
chondrosarcoma
fibrosarcoma
others (ewings, osteoclastoma)
what percent of all ca mets to bone
50%
what percent of lung, breast and prostate ca’s met to bone
> 85
what type of lesions are in 2 bca
lytic or blastic
lytic lesion
space occupying lesion req destr of normal tissue
blastic lesion
lesion uses space to build up
what mnfts are common with secondary bone ca
pain rt inflm, swelling, fractures
what is a major comp of secondary bone ca
fractures
why do fractures occur in secondary bone ca
lytic lesions -> dec stress -> fracture
what medical imaging is used to dx bone ca
xr (only with substantial mets, necrosis, breakdown)
ct mri
what dx is used for bone ca
med imaging
biopsy
bone scan
fx of biopsy in bone ca
confirms malignancy and tells you the type (primary bca)
fx of bone scan in bone ca
may not be req, usually in secondary to confirm mets
tx for bca
chemo,radiation,sx
pain tx
prevent fractures
what type of sx is used in bca
block excision of bone then restorative grafting
