bone formation + bone tumors + bone disorders

Question 1

bones of axial and limb skeletons are formed by

Answer 1

endochondrial ossification

Question 2

bones of skull + facial bones are formed by

Answer 2

membranous ossification

Question 3

bone made by osteoblasts and osteoclasts is first built on a cartilage frame made by chondrocytes in this type of bone formation

Answer 3

endochondrial ossification

Question 4

no cartilage frame in this type of bone formation

Answer 4

membranous ossification

Question 5

epiphyseal plates are an example of this type of bone formation

Answer 5

endochondrial ossification

new bone formation in growing long bones→ lengthen bones, once plates fuse, no more growth

Question 6

sporadic mutation that causes a constitutively active fibroblast growth factor receptor (FGFR3) → inhibits chondrocyte proliferation for endochondrial ossification will cause

Answer 6

achondroplasia

Question 7

risk factor for achondroplasia

Answer 7

advanced paternal age

Question 8

what condition is this:
proximal limbs shorter than distal limbs
limb length disproportionate to trunk length
large head relative to limbs
frontal bossing
bowed tibias
normal lifespan + fertility
AD mutation - 50% chance offspring will get if spouse has no mutation, 2/3 chance living offpsring will get if spouse is also affected

Answer 8

achondroplasia

Question 9

benign primary bone tumor in patient 20-40 yo

Answer 9

osteoclastoma

Question 10

benign primary bone tumor in male

Answer 10

osteochondroma

Question 11

malignant primary bone tumor in male 10-20 yo

Answer 11

osteosarcoma

Question 12

malignant primary bone tumor in boy

Answer 12

ewing sarcoma

Question 13

xray appearance of osteoclastoma

Answer 13

CLean = "soap bubbles" = 
lytic lesion (osteoclast break down bone matrix) = luscent

Question 14

xray appearance of osteochondroma

Answer 14

CHondroma = CHunk of bone =

hamartoma (benign tumor of disorganized tissue in normal location) = bone spur with cartilaginous cap

Question 15

xray appearance of osteosarcoma

Answer 15

SarComa =
Sunburst pattern
Codman’s triangle: elevation of periosteum

Question 16

most common primary malignant bone tumor in children

Answer 16

osteosarcoma (not multiple myeloma - proliferation of plasma cells in bone marrow in elderly)

Question 17

xray appearance of Ewing sarcoma

Answer 17

Wing =think Onion rings = “onion skin” (layers of new bone in periosteum)

Question 18

t(11;22) translocation associated with what primary bone tumor

Answer 18

Ewing Sarcoma

Question 19

primary malignant bone tumor that is aggressive + early mets but responds to chemo

Answer 19

Ewing Sarcoma

Question 20

most common benign primary bone tumor

Answer 20

osteochondroma

Question 21

primary bone tumors that are near the knee

Answer 21

osteoclastoma (benign)

osteosarcoma (malignant)

Question 22

primary tumors with mets to bones

Answer 22

Permanently Relocated Tumors Like Bones
think GU:
Prostate
Renal cell cancer
Testes, thyroid
Lung
Breast

Question 23

metastatic tumor that causes lytic bone lesions (break down bone)

Answer 23

lung

breast (lytic or blastic)

Question 24

metastatic tumor that causes blastic bone lesions (build new bone, disordered, weak, fractures)

Answer 24

prostate

breast (lytic or blastic)

Question 25

is bone mets or primary bone tumor more common

Answer 25

bone mets

Question 26

presentation of bone mets

Answer 26

bone pain epidural spinal cord compression causing neuro sx (BB dysfunction) due to vertebral body lesion hypercalcemia (lytic lesion)

Question 27

bone disease caused by osteoblasts working too slowly allowing ↑ bone resorption by osteoclasts →↓ bone mass and Ca matrix →↑ risk of fracture

Answer 27

osteoporosis

Question 28

bone disease with normal Ca, phosphate, PTH, alk phos

Answer 28

osteoporosis

Question 29

bone disease common in postmenopausal women

Answer 29

osteoporosis

Question 30

complications of osteoporosis

Answer 30

vertebral crush fractures: may have acute back pain, loss of height, leads to kyphosis low trauma fractures (falling to the ground): femoral neck fracture, distal radius fracture

Question 31

diagnosis of osteoporosis by

Answer 31

DEXA scan - bone mineral density test (T

Question 32

treatment of osteoporosis

Answer 32

stop smoking (↓ bone density), alcohol, high dose or chronic glucocorticoid steroid use, avoid PPIs (need acid to absorb Ca), H2 blockers exercise - weight bearing (strain bones → stimulate osteoblasts) vitamin D + vitamin C bisphosphonates (inhibit osteoclast resorption,↓ fracture risk) teriparatide (pulsatile PTH,↓ hip fracture risk) OTHER tx: post-menopausal conjugated estrogen (not used soley for osteoporosis due to SE of MI and CVA,↓ hip fracture risk) if low T, give testosterone (build bones) SERM (raloxifene) (reduce risk of breast cancer,↓ vertebral fracture risk) calcitonin (inhibit osteoclast, not as effective as bisphosphonates, no ↓ fracture risk) denosumab: RANK-L inhibitor (inhibit osteoclast)

Question 33

bone disease where osteoclasts work too slowly → no bone resorption → thick, dense, disorganized bone → ↑ risk of fracture

Answer 33

osteopetrosis

Question 34

bone disease caused by a mutation in the osteoclast carbonic anhydrase II → no bone resorption

Answer 34

osteopetrosis

Question 35

bone disease that may cause: cranial nerve impingement palsies due to narrowed foramina pancytopenia (osteoblasts grow in BM)

Answer 35

osteopetrosis

Question 36

treatment of osteopetrosis

Answer 36

BMT: osteoclasts are derived from monocytes in BM

Question 37

xray appearance of osteopetrosis

Answer 37

bones flare at end, bone-in-bone apperance

Question 38

bone cell that build bone by secreting/laying down collagen and catalyzing the mineralization of the bone matrix

Answer 38

osteoblast

Question 39

when osteoblast is incorporated into the bone it is called an

Answer 39

osteocyte (in the lacune of bony matrix, contact with each other via canalliculi)

Question 40

mutlinucleated bone cell that originated from a monocyte/macrophage, and dissolves bone by secreting acid and collagenases for the goal of releasing Ca into serum or promote remodeling after a fracture

Answer 40

osteoclast

Question 41

bone disease in which osteoclasts break down bony matrix → activates osteoblasts to lay down new matrix osteoclasts burnout due to excess activity → only osteoblasts are working → disorganized bony architecture

Answer 41

Paget disease of bone

Question 42

localized disorder of excess bone remodeling/ bone turnover →↑ alk phos (only lab abnormality)

Answer 42

Paget disease of bone

Question 43

bone disease with increased risk of osteosarcoma

Answer 43

Paget disease of bone

Question 44

alk phos is a marker

Answer 44

``` bone formation (reflects osteoblast activity) other types of alk phos: liver, billirubin ```

Question 45

``` bone disease that can cause: bone pain bone deformaties fractures ↑HAT SIZE (thicker bone) hearing loss (narrowing of auditory foramen) ```

Answer 45

Page disease of bone

Question 46

bone disease in kids caused by vitamin D deficiency

Answer 46

rickets

Question 47

bone disease in adults caused by vitamin D deficiency

Answer 47

osteomalacia

Question 48

bone disease that causes soft bones that bow out

Answer 48

osteomalacia/rickets

Question 49

bone disease that causes defective mineralization and calcification of osteoid due to vitamin D deficiency →↓ serum Ca

Answer 49

osteomalacia/rickets

Question 50

what is the name for cystic bone spaces "brown tumors" lined by osteoclasts filled with fibrous stroma + blood

Answer 50

osteitis fibrosa cystica: a bony manifestation of a endocrine disorder

Question 51

causes of osteitis fibrosis cystica

Answer 51

1° hyperparathryoidism: high PTH → high Ca, low phosphate, high alk phos type 1A pseudohypoparathyroidism = (Albright hereditary osteodystrophy): PTH resistance at renal tubules →no signal to ↑ Ca reabsorption → low serum Ca, high serum phosphate → low serum Ca is trigger to increase PTH in both cases: high PTH → excess osteoclast activity → bone tumors, ↓bone mineral density

Question 52

bone disease in which bone is replaced by collagen + fibroblasts (more collagen than Ca) → irregular bony trabeculae

Answer 52

polyostotic fibrous dysplasia

Question 53

polyostotic fibrous dysplasia is part of this syndrome:

Answer 53

McCune Albright Syndrome: precocious puberty cafe au lait spots fibrous dysplasia of bone

Question 54

treatment for osteomalacia/rickets

Answer 54

vitamin D - reversible!

Question 55

risk factors for osteoporosis

Answer 55

``` old age smoking steroid use chronic heparin use white or asian race thin build lack of exercise poor Ca/D intake low T or low estrogen (menopause) ```