Surgery MSK Flashcards
t/f msk tumors are common
false, bone sarcoma 0.2% of all malignancies, soft tissue sarcomas are <1%
bone tumor evaluation process
- history and pe
- xray of lesion
- lab assessments
- local imaging and cxr
- biopsy
- staging + other exams
t/f age of patient is most important
true, certain bone tumors are more common in certain age groups
table 2
7 xray questions for bone tumor evaluation
- 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
descriptions of bone
- 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)
3 patterns of bone
- marginal sclerosis
- cortical thickening
- periosteal new bone formation
what is marginal sclerosis
- non-aggressive
- gct os more aggressive, does not show marginal sclerosis
what is cortical thickening
- 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
4 sub patterns of periosteal new bone formation
- bone remodeling and endosteal espansion
- neocorticalization
- poorly organized periosteal new bone formation
- muti-level periosteal response or onion peel pattern
what is bone remodeling and endosteal expansion
- expansile remodeling and endosteal scalping
- cortical thinning seen in enchondromas
- seen in non-ossifying fibroma
what is neocorticalization
- non-aggressive tumor destroying original cortex
- periosteum forms new layer of bone to contain the tumor
- gct and enchondroma
what is poorly organized periosteal new bone formation
more in aggressive (osteosarcoma)
what is multi-level periosteal response and onion peel pattern
- 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
what is cortical erosion
- points to aggressiveness
- seen in osteosarcoma and gct
what are soft tissue masses
- gct: locally aggressive, destroy cortex and extend tissue
- osteosarcoma: very aggressive and penetrates through intact cortex and soft tissue
- fibrous dysplasia: confined to bone
4 types of matrix
- osteoid
- chondroid
- ground glass
- lytic lesions or no matrix
what is osteoid matrix
- fluffy, cloudlike, amorphous calcifications
- osteosarcoma
what is chondroid matrix
- stippled, flocculent, or rings and arcs
what is ground glass matrix
- 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
what are lytic lesions or no matrix
- gct, aneurysmal, and unicameral bone cysts and certain metastatic carcinoma (renal cell carcinoma or thyroid)
most useful to see the soft tissue and intramedullary extent of the tumor and to check involvement of major neurovascular structures
mri
benign neoplasms
fibrous: fibrous cortical defect, non-ossifying fibroma, fibrous dysplasia
lytic: unicameral bone cyst, giant cell tumor
osseous lesions: osteoid osteoma
cartilaginous: osteochondroma, enchondroma
what are fibrous cortical defects and non-ossifying fibromas
- 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
what are fibrous dysplasias
- 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
what are unicameral bone cyst
- 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
what are giant cell tumors
- 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
what are osteoid osteoma
- 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
what is an osteochondroma
- 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
what is enchondroma
- 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
malignant bone neoplasms
metastatic carcinoma
marrow and round cell tumors: mm, ewing’s sarcoma
osseous: osteosarcoma
cartilaginous: chondrosarcoma
most common malignancy seen in bone
metastatic ca
- usually in axial skeleton and proximal appendicular skeleton
what are acral metastasis
- metastasis beyond elbow and knee
- spread via arterial circulation
- point to lung primary or lung metastasis
connections of batson’s vertebral vein plexus
- 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
most common primary ca that metastasize to bone
breast, lung, kidney, prostate, thyroid, gi tract
what is multiple myeloma
- > 50 yo
- primary bone marrow tumor from plasma cells
- multiple lytic lesions on skeleton
- punched out lesions, endosteal scalloping, pathologic fractures
- tx: medical
what is ewing’s sarcoma
- 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
what is osteogenic sarcoma
- 10-25 yo
- long bones
- medullary, cortical destruction, permeative borders, aggressive periosteal reaction, osteoid matrix
- lace like histology
- tx: chemo and surgery
most common primary malignancy of bone
osteosarcoma
what is chondrosarcoma
- 30-60 yo
- usually long bones
- lytic, intralesional calcifications, permeative, endosteal scalloping >2/3 of cortex
- lobules of cartilage
- tx:surgery
types of closed biopsy
fnab and core needle
incisional vs excisional biopsy
incisional: peripheral, more sampling errors and less representative
excisional: remove entire mass
enneking surgical staging for msk tumors
table 21
surgical margins for benign stages
table 22
surgical margins for malignant stages
table 23
osteosarcoma tx
1: both surgery and chemo
2: neoadjuvant, surgery, finish chemo (always stage)
surgery in osteosarcoma
- local tumor control: limb sparing resection or limb amputation
- final pathologic evaluation
oncologic surgical margins
read
contraindications for limb salvage
- 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)
what is autograft - vascularized fibular graft
- for long bone defects
- bone is fixed over bone defect and vessel are sutured to vessels of tumor bed
what is recycled autograft - autoclaved
read
what is deep freeze autograft - pedicles frozen recycled autograft
read
what is large segment allograft
- bone bank
what is bone regenration - bone transport
- external fixator
- astronomized
tumor prosthesis and rotationplasty
read
