9.) Benign Bone Forming Tumors

Question 1

What do some consider an osteoma to be?

Answer 1

A hamartoma

Question 2

What is a hamartoma?

Answer 2

Histiologically normal tissue in an abnormal condition

Question 3

Where do osteomas develop?

Answer 3

On intramembranous bones

Question 4

What would be the differential diagnosis of a mass of cortical bone projecting out from the cortex?

Answer 4

Bone island inside the medullary canal

Question 5

What is an osteoma?

Answer 5

Homogeneously dense, painless mass

Question 6

What are the 3 most common locations of an osteoma?

Answer 6

1. ) Calvarium
2. ) Paranasal sinuses
3. ) Mandible (sometimes)

Question 7

What paranasal sinuses are osteomas most commonly found?

Answer 7

Ethmoid and frontal

Question 8

What paranasal sinus are osteomas not commonly found?

Answer 8

Maxillary

Question 9

What is the aka for Gardner Syndrome?

Answer 9

Familial colorectal polyposis

Question 10

What is Gardner Syndrome?

Answer 10

An autosomal dominant form of polyposis characterized by the presence of multiple polyps in the colon together with tumors outside the colon

Question 11

Where are 5 possible locations from the notes of the extracolonic tumors in Gardner Syndrome?

Answer 11

1. ) Osteomas of the skull
2. ) Thyroid cancer
3. ) Epidermoid cysts
4. ) Fibromas
5. ) Desmoid tumors

Question 12

What percent of Gardner Syndrome affected individuals experience an occurrence of desmoid tumors?

Answer 12

15%

Question 13

What are 3 characteristics of osteomas on x-rays?

Answer 13

1.) Typically

Question 14

What is an osteoid osteoma?

Answer 14

A collection of highly vascularlized osteoid tissue and giant cells surrounded by reactive sclerosis of host bone

Question 15

Where are osteoid osteomas most commonly found?

Answer 15

50% in tibia and femur
10% in spine
Long bones

Question 16

What are the 3 benign posterior arch tumors?

Answer 16

1. ) Osteoid Osteoma
2. )
3. )

Question 17

Where are osteoid osteomas found in long bones?

Answer 17

Metaphyseal or diaphyseal

Question 18

Osteoid osteomas make up what percent of all benign primary bone tumors?

Answer 18

11%

Question 19

95% of individuals with osteoid osteomas are diagnosed before what age?

Answer 19

25

Question 20

What is the male to female ratio of those with osteoid osteomas?

Answer 20

2:1

Question 21

What are 3 clinical findings of osteoid osteomas?

Answer 21

1. ) Classic “pain worse at night, relieved by aspirin”
2. ) Typically long history of pain before diagnosis (months-years)
3. ) Lesions may self-resolve over months/years

Question 22

How are osteoid osteomas treated?

Answer 22

En bloc resection

Question 23

What needs to occur in order to avoid an common osteoid osteoma reoccurred?

Answer 23

Nidus must be removed

Question 24

What are 5 x-ray findings of osteoid osteoma?

Answer 24

1. ) Radiolucent nidus is the lesion

2. )

Question 25

What are 3 possible locations of an osteoid osteoma?

Answer 25

1. ) Subperiosteal 2. ) Intracortical 3. ) Intramedullary

Question 26

What is the histological twin to osteoid osteomas?

Answer 26

Osteoblastoma

Question 27

What are 2 clinical findings of an osteoblastoma?

Answer 27

1. ) Long history of pain (typically months-years) | 2. ) Larger, more expansile lesion

Question 28

Where are osteoblastomas most commonly found?

Answer 28

1. ) 30-50% in the posterior arch of the spine | 2. ) 30% in long bones

Question 29

What are the most common long bones to find osteoblastomas?

Answer 29

Femur and tibia

Question 30

What part of the long bone are osteoblastomas found?

Answer 30

Diaphyseal and metadiaphyseal

Question 31

What is the treatment for an osteoblastoma?

Answer 31

Surgical resection

Question 32

What are the 5 x-ray findings of osteoblastomas?

Answer 32

1. ) Expansile, geographic lesion 2. ) May be big; 2-12 cm in diameter 3. ) Matrix lucent, but may have stippled calcification 4. ) Often with sclerotic border and sharp transition zone 5. ) Usually lacks reactive dense reactive sclerosis of the osteoid osteoma

Question 33

What is the second most common primary malignancy of bone?

Answer 33

Osteosarcoma

Question 34

Osteosarcomas is what percent of all primary malignancies of bone?

Answer 34

20%

Question 35

What is the histology of the osteosarcoma?

Answer 35

Spindle-shaped stromal cells, osteoid and intercellular collagenous material

Question 36

75% of osteosarcoma cases occur between what ages?

Answer 36

10-25 years

Question 37

What is the male to female ratio of the osteosarcoma?

Answer 37

2:1

Question 38

What are 5 clinical findings of osteosarcomas?

Answer 38

1. ) Local pain 2. ) Enlarging mass 3. ) Swelling 4. ) Redness 5. ) Elevated serum alkaline phosphatase

Question 39

What are the 3 "conventional" or most common subtypes of osteosarcomas?

Answer 39

1. ) Parosteal osteosarcoma 2. ) Periosteal osteosarcoma 3. ) Multicentric osteosarcoma

Question 40

Where is the osteosarcoma most commonly found?

Answer 40

Knees and proximal humerus (but reported almost everywhere)

Question 41

What part of the long bone are osteosarcomas found?

Answer 41

Metaphysis

Question 42

What percent of osteosarcomas are found in the spine?

Answer 42

5-7%

Question 43

What are the 3 basic patterns of osteosarcomas?

Answer 43

50% sclerotic 25% lytic 25% mixed

Question 44

What are 5 x-ray findings of osteosarcomas?

Answer 44

1. ) Soft tissue mass with calcification and/or ossification 2. ) Periosteal reaction is classically Sunburst or spiculated 3. ) Premeative or moth-eaten lysis 4. ) Bone to bone metastasis is not common but may occur 5. ) Multiple primaries rare, but reported

Question 45

What is the treatment for osteosarcomas?

Answer 45

Amputation and chemo

Question 46

What is the survival rate of osteosarcomas?

Answer 46

20%

Question 47

Secondary osteosarcoma may develop from what 3 things?

Answer 47

1. ) Paget's disease 2. ) HME 3. ) Following radiation therapy of benign lesions

Question 48

What is the aka for Parosteal osteosarcoma?

Answer 48

Juxtacortical sarcoma

Question 49

What are 5 clinical findings of a parosteal oseosarcoma?

Answer 49

1. ) Slower growing and less aggressive than typical osteosarcoma 2. ) Older age group than typical osteosarcoma (2nd-4th decades) 3. ) Mild; hard local mass/swelling fixed to a bone 4. ) Variable length of symptoms but typically 2-6 months 5. ) Alkaline phosphate and other labs often WNL

Question 50

Parosteal osteosarcomas almost exclusively affects what bones?

Answer 50

Long bones

Question 51

92% of parosteal osteosarcomas are found in what 3 locations?

Answer 51

1. ) Femur 2. ) Tibia 3. ) Humerus

Question 52

8% of parosteal osteosarcomas are found in what 3 locations?

Answer 52

1. ) Fibula 2. ) Radius 3. ) Ulna

Question 53

What are the 2 basic types of juxtacortical sarcomas?

Answer 53

1. ) Parosteal osteosarcoma | 2. ) Parosteal osteogenic sarcoma

Question 54

How are the 2 juxtacortical sarcomas differentiated?

Answer 54

Based on relative amounts of fibrous, cartilage and osteoid tissue present