Surgery MSK

Question 1

t/f msk tumors are common

Answer 1

false, bone sarcoma 0.2% of all malignancies, soft tissue sarcomas are <1%

Question 2

bone tumor evaluation process

Answer 2

• history and pe
• xray of lesion
• lab assessments
• local imaging and cxr
• biopsy
• staging + other exams

Question 3

t/f age of patient is most important

Answer 3

true, certain bone tumors are more common in certain age groups

table 2

Question 4

7 xray questions for bone tumor evaluation

Answer 4

- location
aggressiveness
- how large (compared to bone)
- how extensive
- what is the lesion doing to the bone
- what is the bone doing in response
- is there a cortical lesion
- is there soft tissue mass
histology
- what is the matrix

Question 5

descriptions of bone

Answer 5

• geographic: margins are sharp and zone of transition is narrow (non-aggressive)
• moth eaten: multiple lytic lesions in bone (myeloma or metastatic ca)
• permeative pattern: ill defined margin and wide zone of transition (osteogenic sarcoma)

Question 6

3 patterns of bone

Answer 6

• marginal sclerosis
• cortical thickening
• periosteal new bone formation

Question 7

what is marginal sclerosis

Answer 7

• non-aggressive

- gct os more aggressive, does not show marginal sclerosis

Question 8

what is cortical thickening

Answer 8

• high concentrations of pde2 = pain relieved by nsaids
• pge2 = stimulates osteoblasts = bone thickening
• osteofibrous dysplasia is seen in pedia pts, benign lesion involving anterior cortex of tibia

Question 9

4 sub patterns of periosteal new bone formation

Answer 9

• bone remodeling and endosteal espansion
• neocorticalization
• poorly organized periosteal new bone formation
• muti-level periosteal response or onion peel pattern

Question 10

what is bone remodeling and endosteal expansion

Answer 10

• expansile remodeling and endosteal scalping
• cortical thinning seen in enchondromas
• seen in non-ossifying fibroma

Question 11

what is neocorticalization

Answer 11

• non-aggressive tumor destroying original cortex
• periosteum forms new layer of bone to contain the tumor
• gct and enchondroma

Question 12

what is poorly organized periosteal new bone formation

Answer 12

more in aggressive (osteosarcoma)

Question 13

what is multi-level periosteal response and onion peel pattern

Answer 13

• periosteum being lifted by tumor = onion peel patter
• ewing’s sarcoma, osteosarcoma, osteomyelitis
• condmans triangel: original cortex, lifted periosteum, tumor
• more in aggresive tumos (osteosatcoma)
• hair on head or sunburst pattern

Question 14

what is cortical erosion

Answer 14

• points to aggressiveness

- seen in osteosarcoma and gct

Question 15

what are soft tissue masses

Answer 15

• gct: locally aggressive, destroy cortex and extend tissue
• osteosarcoma: very aggressive and penetrates through intact cortex and soft tissue
• fibrous dysplasia: confined to bone

Question 16

4 types of matrix

Answer 16

• osteoid
• chondroid
• ground glass
• lytic lesions or no matrix

Question 17

what is osteoid matrix

Answer 17

• fluffy, cloudlike, amorphous calcifications

- osteosarcoma

Question 18

what is chondroid matrix

Answer 18

• stippled, flocculent, or rings and arcs

Question 19

what is ground glass matrix

Answer 19

• fibrous dysplasia
• bone does not mature to lamellar bone but remains as woven bone interspersed within a fibrous background
• when found on the hip = coxa vara or shepherd’s crook deformity

Question 20

what are lytic lesions or no matrix

Answer 20

• gct, aneurysmal, and unicameral bone cysts and certain metastatic carcinoma (renal cell carcinoma or thyroid)

Question 21

most useful to see the soft tissue and intramedullary extent of the tumor and to check involvement of major neurovascular structures

Answer 21

mri

Question 22

benign neoplasms

Answer 22

fibrous: fibrous cortical defect, non-ossifying fibroma, fibrous dysplasia
lytic: unicameral bone cyst, giant cell tumor
osseous lesions: osteoid osteoma
cartilaginous: osteochondroma, enchondroma

Question 23

what are fibrous cortical defects and non-ossifying fibromas

Answer 23

• age: children and adolescents
• site: metaphyseal cortical defect, long bones
• fcd: <2-3 cm, nof >3 cm
• geographic borders
• sclerotic rim
• dx: incidental on xray
• tx :if symptomatic, needs surgery

Question 24

what are fibrous dysplasias

Answer 24

• age: monoostotic any age, 5-20 yrs
• age: polyostotic any age
• ground glass matrix
• due to failure of bone to mature to lamellar bone causing deformities

Question 25

what are unicameral bone cyst

Answer 25

- age: 4-13 - proximal humerus, femur, metaphyseal to disphyseal - central lytic lesion - geographic - no soft tissue component - fallen leaf sign!!! (broken bone cortex at bottom of cyst - resolves as skeleton matures - can have pathologic fractures

Question 26

what are giant cell tumors

Answer 26

- skeletally mature 20-30 - epimetaphyseal, around knee, distal radius - no matrix (lytic) - cortices thinned out, expanded, or deficient with soft tissue extension - can be locally aggressive - tx: medical and surgery

Question 27

what are osteoid osteoma

Answer 27

- age 10-30 - usually cortical - small, 1-2 cm lucent nidus with surrounding sclerotic reaction (thick bone) - high pge2 in nidus = pain and stimulates osteoblasts to produce bone - pain relieved by nsaids - tx: ablation of nidus

Question 28

what is an osteochondroma

Answer 28

- 10 yo, <20 - surface lesion, metaphyseal - sessile or pedunculated bony outgrowth with cartilaginous cap - +/- calcifications - due to abnormal growth of bone perpendicular to epiphysis - growth after maturity = metastasis

Question 29

what is enchondroma

Answer 29

- 15-40 yo - within shafts of long tubular bones, hands, and feet - chondroid matrix, endosteal scalloping, no cortical break, no soft tissue extension - long bones - symptomatic: curettage and bone graft - long bone destruction - malignant degeneration

Question 30

malignant bone neoplasms

Answer 30

metastatic carcinoma marrow and round cell tumors: mm, ewing's sarcoma osseous: osteosarcoma cartilaginous: chondrosarcoma

Question 31

most common malignancy seen in bone

Answer 31

metastatic ca | - usually in axial skeleton and proximal appendicular skeleton

Question 32

what are acral metastasis

Answer 32

- metastasis beyond elbow and knee - spread via arterial circulation - point to lung primary or lung metastasis

Question 33

connections of batson's vertebral vein plexus

Answer 33

- breast, lung, kidney prostate thyroid - vertebral bodies pelvis ribs skull proximal limb girdle - no venous valves - inc pressure in lungs and abdomen = bypass heart and lungs = flow into vertebral plexus of veins

Question 34

most common primary ca that metastasize to bone

Answer 34

breast, lung, kidney, prostate, thyroid, gi tract

Question 35

what is multiple myeloma

Answer 35

- >50 yo - primary bone marrow tumor from plasma cells - multiple lytic lesions on skeleton - punched out lesions, endosteal scalloping, pathologic fractures - tx: medical

Question 36

what is ewing's sarcoma

Answer 36

- usually children and young adults - on long bones and pelvis - round cell tumors - "moth eaten" appearance - destructive permeative lesions with soft tissue component - tx: chemo, radio, surgery

Question 37

what is osteogenic sarcoma

Answer 37

- 10-25 yo - long bones - medullary, cortical destruction, permeative borders, aggressive periosteal reaction, osteoid matrix - lace like histology - tx: chemo and surgery

Question 38

most common primary malignancy of bone

Answer 38

osteosarcoma

Question 39

what is chondrosarcoma

Answer 39

- 30-60 yo - usually long bones - lytic, intralesional calcifications, permeative, endosteal scalloping >2/3 of cortex - lobules of cartilage - tx:surgery

Question 40

types of closed biopsy

Answer 40

fnab and core needle

Question 41

incisional vs excisional biopsy

Answer 41

incisional: peripheral, more sampling errors and less representative excisional: remove entire mass

Question 42

enneking surgical staging for msk tumors

Answer 42

table 21

Question 43

surgical margins for benign stages

Answer 43

table 22

Question 44

surgical margins for malignant stages

Answer 44

table 23

Question 45

osteosarcoma tx

Answer 45

1: both surgery and chemo 2: neoadjuvant, surgery, finish chemo (always stage)

Question 46

surgery in osteosarcoma

Answer 46

- local tumor control: limb sparing resection or limb amputation - final pathologic evaluation

Question 47

oncologic surgical margins

Answer 47

read

Question 48

contraindications for limb salvage

Answer 48

- surgical margins are inadequate - survival is not expected to exceed 3 mos - gross contamination with tumor (poorly performed biopsy, certain pathologic fractures, inadvertent surgery with unresectable positive margins)

Question 49

what is autograft - vascularized fibular graft

Answer 49

- for long bone defects | - bone is fixed over bone defect and vessel are sutured to vessels of tumor bed

Question 50

what is recycled autograft - autoclaved

Answer 50

read

Question 51

what is deep freeze autograft - pedicles frozen recycled autograft

Answer 51

read

Question 52

what is large segment allograft

Answer 52

- bone bank

Question 53

what is bone regenration - bone transport

Answer 53

- external fixator | - astronomized

Question 54

tumor prosthesis and rotationplasty

Answer 54

read