Unit 23

Question 1

why is secondary bone ca (BCA) common

Answer 1

because of inc vascularity of bone -> inc blood moves here -> inc probablity of emboli to move thru bone

Question 2

where does most bone growth occur

Answer 2

metaphysis

Question 3

what does bone form from

Answer 3

cartildige

Question 4

why is identification of primary bca hard

Answer 4

diverse types

Question 5

what do we identify bone ca based on

Answer 5

histology

location of ca in skeleton and in bone itself

Question 6

what type of tumor is osteosarcoma

Answer 6

bone forming

Question 7

how common is osteosarcoma

Answer 7

most common

Question 8

where does osteosarcoma usually originate (skeleton)

Answer 8

around knee

Question 9

characteristics of mets in osteosarcoma

Answer 9

quick and easy, to lung

Question 10

what pts does 75% of osteosarcoma occur in

Answer 10

pts under 20

Question 11

why does most osteosarcoma occur in young pts

Answer 11

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

Question 12

what pts does 25 % of osteosarcoma occur in

Answer 12

geri pts with underlying pathologic bone disease eg pagets

Question 13

why does 25% of osteosarcoma occur in geri puts

Answer 13

pts with bone diseaes have inc resoprtion and formation of bone, this means there is still cell prolif/dna replication -> risk for gene mutatin

Question 14

other primary malignancies

Answer 14

chondrosarcoma
fibrosarcoma
others (ewings, osteoclastoma)

Question 15

what percent of all ca mets to bone

Answer 15

50%

Question 16

what percent of lung, breast and prostate ca’s met to bone

Answer 16

> 85

Question 17

what type of lesions are in 2 bca

Answer 17

lytic or blastic

Question 18

lytic lesion

Answer 18

space occupying lesion req destr of normal tissue

Question 19

blastic lesion

Answer 19

lesion uses space to build up

Question 20

what mnfts are common with secondary bone ca

Answer 20

pain rt inflm, swelling, fractures

Question 21

what is a major comp of secondary bone ca

Answer 21

fractures

Question 22

why do fractures occur in secondary bone ca

Answer 22

lytic lesions -> dec stress -> fracture

Question 23

what medical imaging is used to dx bone ca

Answer 23

xr (only with substantial mets, necrosis, breakdown)

ct mri

Question 24

what dx is used for bone ca

Answer 24

med imaging
biopsy
bone scan

Question 25

fx of biopsy in bone ca

Answer 25

confirms malignancy and tells you the type (primary bca)

Question 26

fx of bone scan in bone ca

Answer 26

may not be req, usually in secondary to confirm mets

Question 27

tx for bca

Answer 27

chemo,radiation,sx
pain tx
prevent fractures

Question 28

what type of sx is used in bca

Answer 28

block excision of bone then restorative grafting