B6.067 Bone Tumors Flashcards
benign lesions in 0-5
eosinophilic granuloma (EG) (osteomyelitis)
malignant lesions in 0-5
leukemia (ALL)
mets (neuroblastoma)
limited but significant ddx
benign lesions in 5-10
unicameral bone cyst
non-ossifying fibroma (NOF)
osteochondroma
malignant lesions in 5-10
Ewing sarcoma
what is an NOF
non ossifying fibroma
developmental abnormality where scar tissue is present in place of bone
benign lesions 10-20
osteoid osteoma
bone cysts
chondroblastoma
malignant lesions 10-20
osteosarcoma
Ewing sarcoma
benign lesions in adults
enchondroma
giant cell tumor
malignant lesions in adults
chondrosarcoma
metastasis
lymphoma
myeloma
most common symptom of bone tumors
pain
nerve endings in the periosteum respond to compression of tumor
do soft tissue tumors present with pain?
not unless they run into the bone
characteristics of pain to examine
duration -weeks/months : tumor -days/ weeks: inflamm mechanical vs resting recent trauma or injury
what are 2 different etiologies of soft tissue mass
bone tumor extending into soft tissue
OR
tumor of the soft tissue
2nd most common symptoms of bone tumor
soft tissue mass
characteristics of soft tissue masses to examine / ddx
days/weeks after injury: myositis ossificans
painful mass over days: infection
enlarging painless mass: soft tissue tumor
enlarging painful mass: bone tumor
progressive hematoma after trauma : tumor
why is a progressive hematoma after trauma worrisome
should NOT continue to grow under normal circumstances
likely caused by tumor angiogenesis factor producing friable blood vessels around the tumor
these more likely to continue to bleed than normal BVs without tumor growth
evaluation of possible bone tumor
size of mass neuro status (involving nerve?) tenderness range of motion of adjacent joints local/distant nodes
would you see node involvement in osteosarcoma?
NO
spread via blood, not to nodes
see lung involvement most commonly
most common location of bone tumors
metaphysis
intramedullary
vertebral body is similar to the ______ of long bones
metaphysis
more likely tumor location
posterior spinal elements are similar to _______ of long bones
diaphysis
more cortical bone
less common tumor location
types of tumor margins
geographic
moth-eaten
permeative
concerning tumor margin patterns
moth eaten
permeative
cannot demarcate the transition between normal and abnormal bone
both are present, but no clear line
geographic tumor margin
sharp transition between abnormal and normal bone
benign
what to look for on radiographs of bone tumors
what is tumor doing to bone?
what is bone doing to tumor?
what is in the matrix or the lesion?
options for what could be the matrix composition inside a tumor of the bone
no matrix = fluid, blood, fibrous tissue
dense = bone, osteonecrosis
“popcorn” = cartilage
“ground glass” = osteoid
when do you use MRI
assess soft tissues and bone marrow extent
when do you use CT
bone integrity
mineralization pattern
systemic involvement assessment (metastasis)
when do you use a bone scan
determine degree of activity of known bone involvement or to look for other areas of bone involvement (assessing for mets in bone sarcomas or other sites of disease in polyostotic benign lesions)
do sarcomas typically have multiple bone lesions?
no
what are some diseases that can present with multiple bone lesions
osteochondroma metastases leukemia enchondroma fibrous dysplasia Langerhans cell histiocytosis non-ossifying fibromas/ fibrous cortical defects
xray findings in osteosarcoma
permeative margin
dense area of bone growth
soft tissue expansion possible (fuzzy white outline)
Tc99 bone scan findings on osteosarcoma
increased uptake in location of tumor
how do you excise a osteosarcoma?
WIDE margins
tumor + normal tissue around it
histo features of osteosarcoma
mitotic figures in tumor cells surrounded by pink osteoid substance
common locations for osteosarcoma
areas around growth plates knee (50%) hip (15%) shoulder (10%) jaw (8%)
most common primary malignant bone tumor
osteosarcoma
age distribution of osteosarcoma
bimodal distribution
75% in pts < 20, most commonly when kids have rapid growth period
other peak between 60s-80s, usually a result of a preexisting lesion
genetic predisposition to osteosarcoma
mutations in p53 and RB
hereditary RB are 1000x more likely to develop osteosarcoma
MOST PEOPLE DONT HAVE AN IDENTIFIABLE MUTATION THO
associations with osteosarcoma in adults
bone infarcts chronic osteomyelitis Paget radiation bone neoplasia WORSE in adults...many die
progressive knee pain in kiddos
osteosarcoma until proven otherwise
even if there was trauma
treatment for osteosarcoma
start on systemic chemo immediately, even if lung and bone scans do not show mets
could be micromets that aren’t visible
DOES NOT respond to radiation
surgical excision of primary tumor
what determines reconstructive potential of a limb after tumor excision?
amount of soft tissue structures intact
nerve and muscles need to be able to power the extremity
amputation f this stuff isn’t left
what is true of ambulating with a prosthesis?
work well but require more energy than walking with a reconstructed extremity
important if patient has compromised cardiac or pulm status
options for reconstruction
allograft - frozen from bone bank
megaprosthesis - joint replacement where segments can be added to grow w patient
rotationplasty
what is the general rule of thumb about using a megaprosthesis
don’t use in patients < 7-8
you lose growth plates
cant grow enough to keep up with patient, will lead to large limb length discrepancy
who is a good candidate for a rotationplasty?
younger kids > older kids
younger kids will have less psychiatric concern with having to completely learn how to use a new limb
what happens in a rotationplasty
connect tibia to proximal femur with heel on anterior of patient
ankle functions as a knee joint
advantages of rotationplasty
better psych outcomes in young patients limited phantom pain standing/walking on weight bearing surfaces (soles of feet used to pressure, don't get torn up in prosthetic) control for limb length discrepancy good activity level more durable in kids than endoprosthesis
xray findings in chrondrosarcoma
expansile lesion
characteristic punctate calcifications (popcorn)
what is a 4 corner amputations
arm
clavicle
scapula
usually try really hard to save upper extremities but you gotta do what you gotta do ya know
normal cartilage histo
group of 2-3 cells per lacuna
lots of pink matrix between cell groups
enchonroma
benign cartilage tumor
enchondroma histo
increased cellularity from regular cartilage
matrix still present tho
normal nuclei
chondrosarcoma histo
decreased matrix
increased cellularity
abnormal nuclei with multiple mitotic figures
most common primary bone tumor in adults
chondrosarcoma
common locations for chondrosarcoma
shoulder girdle
hip/pelvis
treatment of chrondrosarcoma
surgical excision
chemo for rare variant, but in general doesn’t respond to chemo
additional imaging needed in chondrosarcoma
CT chest to check for lung mets
needed in all sarcomas
imaging findings in Ewings sarcoma
permeative lesion
MRI shows extensive marrow involvement
subperiosteal edema
treatment options for Ewings
surgical resection or radiation
radiation can damage growth plate in kids
histo of Ewings
small/round blue cell tumor
sheets of small cells with inconspicuous cytoplasm
epidemiology of Ewings
most patients are < 20
second most common bone tumor in kids (after osteosarcoma)
more common in Caucasians
slightly more common in boys
symptoms of Ewings
pain, fever, leukocytosis
SUPER important to distinguish from osteomyelitis
can appear identically until biopsied
where does Ewings occur
diaphysis/metaphysis of long bones
Ddx of Ewings based on histo
metastatic neuroblastoma
metastatic rhabdomyosarcoma
lymphoma
genetics associated with Ewings
85% t(11;22)
5-10% t(21;22)
1% t(7;22)
in ALL cases: fusion of EWS gene on chromosome 22 to a member of the ETS family of transcription factors (most commonly FLI1)
EWs-FLI1 fusion gene
acts as a dominant oncogene constitutively active transcription factor that stimulates cell proliferation
prognosis of Ewings
75% 5 year survival
50% long term cure
hardest location of Ewings to cure
pelvis
hard to excise
epidemiology of soft tissue tumors
much more common than bone tumors
most are benign
lipoma most common
how to determine origin of soft tissue tumor
evaluate initially with plain films to determine if mass is coming from bone or soft tissue and to evaluate for any mineralization within the lesion
epidemiology of soft tissue vs bone malignancies
malignant primary bone tumors occur in younger patients
malignant soft tissue tumors are more common among adults
most common location of synovial sarcoma
buttock
if u said synovium you truly SUCKKKKK
epidemiology of synovial sarcoma
3rd most common type of soft tissue sarcoma (most common among teenagers)
appearance of synovial sarcoma on MRI
mass that is made of something between fat and fluid
histo of synovial sarcoma
typically biphasic tumor
-spindle cells
-glandular epithelial cells
can have monophasic, spindle cell variant (in men) that is only detected by translocation
genetics associated with synovial sarcoma
t(X;18)
treatment of synovial sarcoma
radiation therapy
wide resection
