Bone Tumors Flashcards
2 types of bone tumors
- primary: from bone cells
- secondary: mets from breast, prostate, lungs, thyroid & kidneys
what genes normally help cells grow and divide / help cells stay alive
Proto-oncogenes
what two “benign” bone tumors weaken the bone?
- Osteoid osteoma
- Osteochondroma
- Dull ache
- Worse with activity
- Progresses over time
- +/- soft tissue mass firmly attached to bone
- Constitutional sx are late findings (mets)
what type of bone tumor
malignant
initial imaging study of choice for bone tumors?
XR
on XR
- Well-defined or sclerotic border
- Sharp zone of transition
- Small size or multiple lesions
- Confinement by natural barriers (eg, growth plate, cortex)
- Lack of destruction of cortex
- Lack of extension into soft tissue
what type of bone tumor?
benign
characteristics of a malignant bone tumor on XR
- Poorly defined borders
- Cortical destruction (“moth-eaten” or permeative pattern)
- Spiculated or interrupted periosteal reaction
- Extension into the soft tissue
- Large size
A benign, well-defined, expansile lesion with regular destruction of cortical bone and a peripheral layer of new bone.
Chondromyxoid fibroma
A locally aggressive lesion w/ cortical destruction, expansion and a thin, interrupted peripheral layer of new bone.
Giant cell tumor
other w/u for bone tumor after XR
- CT scan - Best for assessing metastatic disease in thorax
- MRI - Determines tumor size, extent of intraosseous and extraosseous involvement, Add contrast for bx
Cartilage-forming tumors
- Osteochondromas
- Enchondroma
- Chondroblastoma
- Fibrous lesions
- Cystic tumors
osteoid osteoma is an overgrowth of bone tissue arises from ?
osteoblasts
osteoid osteoma MC where on the bone?
In long bones - femur MC
As bone tissue proliferates, a _____ is formed
osteoid osteoma
nidus surrounded by sclerotic bone
a centrally located disorganized mixture of small blood vessels, trabecula (tiny rods of bone), and osteoid (unmineralized bony tissue)
Nidus
The nidus secretes _____ leading to the pain associated with this tumor
prostaglandins
- Localized, deep, constant, aching pain
- Worse at PM, waking patient up; occasionally worse with activity and ETOH use1
- Improves with NSAID or ASA - +/- palpable mass, tenderness overlying the lesion, neurologic symptoms
- Atypical juxta-articular presentation
- Pain in joint (hip - MC) with walking with limp
- Referred pain to the knee
osteoid osteoma
w/u for osteoid osteoma
- XR
- CT w/ IV contrast - preferred imaging following XR
- Radionuclide Scanning (aka Bone Scan)
- MRI with gadolinium
osteoid osteoma findings on XR?
- sclerosis around a lucent nidus (< 1.5 cm)
- Varying presentations
- Calcified nidus = radiopaque point called the bell
- Nidus close to bone surface may appear like fx
indications for CT w/ Contrast for osteoid osteoma?
- X-ray appears abnormal, but nidus isn’t visible
- Residual or recurrent tumor is present
- Tumor in a critical area - Spine, Femoral neck
- Indicated when XR is normal
- More sensitive > XR
what imaging for osteoid osteoma?
what is the diagnostic finding?
- Radionuclide Scanning (aka Bone Scan)
- “Double density”
- Less accurate < CT d/t reactivity of bone from edema surrounding lesion
- Often used to assess cases not confirmed by XR or CT
MRI with gadolinium
mgmt for osteoid osteoma
- OTC tx, serial imaging q 4-6 mo
- symptomatic / uncontrolled - refer, surgical intervention - Resection vs radiofrequency ablation vs cryotherapy; Removal of nidus
T/F: osteoid osteomas can resolve spontaneously over several years
T
- Morphologically and genetically similar to osteoid osteoma
- slow growing
- May be more aggressive = more bony and soft tissue destruction
- Nidus > 2 cm²
dx?
osteoblastoma
osteoblastoma MC location?
Posterior column of spine → spinous process, lamina, and pedicles
- Chronic pain (dull and achy) → Unrelieved by NSAIDs
- sx dependent on tumor location
- LE → limp
- Spinal cord/nerve root compression → limp or neurologic sx
- Spine → scoliosis - Rarely any systemic sx
osteoblastoma
w/u and findings for osteoblastoma
- XR - Well-circumscribed radiolucent lesion (nidus) > 2 cm; Thin shell of peripheral new bone separating it from surrounding soft tissue; Spinal lesions extend into soft tissue
- CT - indicated for all osteoblastoma
- MRI
- Bx - core needle vs open bx
mgmt for osteoblastoma
- surgical resection - Curettage and burring followed by bone grafting; Marginal resection
- +/- Post-surgical radiation if entire lesion can not be resected
when is marginal resection performed for osteoblastoma?
- Reserved for more aggressive tumors
- Results in more healthy bone being removed
prognosis for osteoblastoma
- Reported recurrence rate 10-20%
- relapse associated w/ inadequate resection of primary lesion - Some lesions may not be able to be fully resected due to location (i.e. spine)
- MC solitary, benign bone tumor
- Benign, cartilage-capped bony projection on the external surface of a bone - Osteocartilaginous exostosis
- Males > females
- MC present in 2nd decade
OSTEOCHONDROMA
osteochondroma MC happens where?
- knee and proximal humerus
- Other common sites: pelvis and scapula
osteochrondroma occurs adjacent to what layer/part of the bone?
when does tumor stop growing?
- epiphyseal growth plate
- when growth plates close
causes of osteochondroma
- Solitary tumors – unknown
- Hereditary multiple osteochondromas (HMO)
- genetic mutation in tumor suppressor genes EXT1 or EXT2
- MC asx and found incidentally on imaging
- Painless mass near a joint or on axial skeleton
- Mechanical sx - Bursitis over exostosis; Irritation to tendons, muscles, or nerves
- Painful mass assoc w/ local trauma
- Growth plate dysfunction - Varus or valgus deformity; Shortening of long bone
osteochondroma
w/u for osteochondroma and findings?
- XR - Bone spur that extends away from joint
- CT/MRI - further assess lesions not defined on XR (Pelvis, scapula, spine)
- Helps with localization and surgical planning
- MRI preferred if looking at soft tissue
mgmt for osteochondroma
- Asx - No intervention, annual w/ clinical exam; any change → MRI
- Surgical excision
- Refer to orthopedic oncology if surgical excision is considered
Surgical excision indications for osteochondroma
- Large lesion, associated with deformity and functional limitations
- Concern malignant transformation
complications of osteochondroma
- < 1% risk of chondrosarcoma
- Higher risk in HMO
- Suspected if: New onset growth of lesion, New onset pain, Rapid growth of lesion
prognosis of osteochondroma
- Solitary osteochondromas
- Excellent local control w/ surgical excision
- recurrence rate < 2% - Hereditary multiple osteochondromas
- Monitor for growth defects and neuro changes (spinal lesion)
- A benign cartilage forming tumor that develops in bone marrow of long bones
- Lesions replace normal bone with hyaline cartilage
enchondroma
enchondroma growth occurs where on the bone?
pathophys
from metaphysis into diaphysis
Theory: lesion arises in growth plate d/t failure of downregulation of growth plate chondrocytes
enchondroma MC occurs where?
- MC – hands and feet
- Other sites: Humerus, Femur, Tibia, Ribs
- A non-hereditary, acquired genetic mutation resulting in multiple enchondromas, often with a unilateral predominance
- Usually presents before age 10
Enchondromatosis
s/s of enchondroma
- MC asx
- Widening of the bone, Angular deformity, Limb-length discrepancy
- Pain from pathologic fx MC in wt bearing bones
w/u for enchondroma
- XR
- Bone scan - Test negative if uncomplicated; Areas of activity = pathologic fx or malignant dx (chondrosarcoma)
- CT/MRI - r/o ddx of chondrosarcoma or bone infarct
- Bx - If painful w/o fracture = r/o chondrosarcoma
XR findings of enchondroma
- Centrally located
- Round or oval
- Well circumscribed
- Sclerotic border
- Lobulations are often seen inside the lesion
mgmt for enchondroma
- Small, asx- Monitor w/ exam and imaging
-
Sx/pathological fx risks - Curettage & bone grafting
- heal fx before curettage
Pathologic Fx Risk Factors
- wt bearing bone
- > 25 mm in diameter
- Involving > 50% of diameter of cortex
prognosis of enchondroma
- Solitary: self-limiting, continued growth possible
- Recurrence rare after curettage & graft
- long bones & pelvis: can transform into chondrosarcomas
- Rare in solitary lesions
- 50% of enchondromatosis
A benign cartilage-forming tumor that usually arises in the epiphyses or apophyses of long bones
CHONDROBLASTOMA
chondroblastoma MC sites?
- Epiphysis of proximal humerus
- Distal femur
- Proximal tibia
s/s of chondroblastoma
- Chronic pain - mild and progressive; constant and unrelated to activity
- Joint stiffness and swelling
- Localized tenderness
- Dec ROM
- Joint effusion
- Muscle atrophy
- Limp in wt bearing lesions
XR finding of a small, well-defined lesions with sclerotic border that may cross the physis (growth plate)
dx?
chondroblastoma
tx for chondroblastoma
surgery - curettage and bone grafting
complication of chondroblastoma?
Benign pulm mets
- CXR in all; follow w/ CT w/ IV contrast if any suspicious areas are present
- resectable and curable
- Abnml fibrous tissue and trabecular bone replaces nml bone marrow and bone tissue = bone weakness
- Resulting in Fx or deformity
- Lesion is slow growing and often appears during periods of bone growth
fibrous dysplasia
associated genetic condition with fibrous dysplasia?
McCune-Albright Syndrome
Polyostotic lesions, ipsilateral café-au-lait spots, precocious puberty
common sites for fibrous dysplasia
- Proximal femur
- Tibia
- Skull/maxilla
- Ribs
s/s of fibrous dysplasia
- MC asx
- Pain/tenderness as fibrous tissue expands into bone or fx happens
- Bone deformity - Shepherd’s Crook, Scoliosis, leg length discrepancy, Facial asymmetry
- Rib deformities
- Swelling
- Waddling gait
XR shows Lytic lesion with “ground-glass” appearance
dx?
fibrous dysplasia
indications to use bone scan for fibrous dysplasia?
r/o polyostotic disease
tx fibrous dysplasia
- asx - monitor w/ serial exams and imaging
-
Curettage & bone grafting; recurrence HIGH
- Avoided in peds: high rate of recurrence - IV bisphosphonates
- Rigid fixation w/ intramedullary implant
- Refer to endo if polyostotic lesions present
A destructive, deforming, slow growing benign fibro-osseous lesion
ossifying fibroma
MC sites for ossifying fibroma
- tibia and fibula - < 10 y/o – peaks 1-5 y/o
- mandible - adults
s/s of ossifying fibroma
- Localized, firm swelling
- Tibia bowed anteriorly or anterolaterally
- painless
- Pain - associated with pathologic fx
XR finding of ossifying fibroma
- Well-circumscribed intracortical lesion
- Cortex expanded and thinned, with multiple radiolucencies (lytic appearing)
tx for ossifying fibroma
- Asx - monitored, repeat imaging q 6 mo
-
Resection, curettage & bone grafting after skeletal maturity
- curative
- performed before: risk of recurrence
- benign, non-aggressive tumor that consists mainly of fibrous tissue
- MC benign bone lesion in children
nonossifying fibroma
MC sites for nonossifying fibroma
- Distal femur
- distal and proximal tibia
s/s of nonossifying fibroma
- MC asx
- Larger lesions = bone weakness = fx
XR for nonossifying fibroma
- Small, well-defined, eccentric, lytic lesions
- MC distal diaphysis/metaphysis
- Sometimes multiple lesions may occur
tx nonossifying fibroma
- Asx small - none
- Indications for curettage and grafting:
- Lesions > 50% of bone diameter
- Lesions in high stress area (distal femur)
- simple bone cysts or solitary bone cysts
- Non-cancerous fluid filled lesions with fibrous lining
unicameral bone cysts
MC sites for unicameral bone cysts
- Proximal humerus
- Proximal femur
s/s unicameral bone cysts
- Asx until pathologic fx - pain, limp, or inability to use extremity
- Lesions occurring within a growth plate - growth plate dysfunction & limb length discrepancy
XR:
* Well defined, cystic lesions at metaphysis or metadiaphysis
* involves entire diameter of bone
* Pathologic fx - “fallen leaf” or “fallen fragment” sign
dx?
unicameral bone cysts
tx for unicameral bone cysts
- resolution after skeletal maturity
- Asx - Observe w/ serial XR q 4-6 mo; Activity restrictions
- risk of fx - Cyst Aspiration and injection of methylprednisolone or bone marrow
- Curettage & bone grafting - for larger cysts that compromise the structural integrity of bone
- A benign, rapidly growing and destructive blood-filled lesion
- Lesions are usually solitary
- Females > males
- MC in adolescents
aneurysmal bone cyst
MC sites for aneurysmal bone cysts
- Tibia
- Femur
- Posterior vertebral elements
- Pelvis
- Humerus
- Fibula, foot, hand, ulna, radius
s/s of aneurysmal bone cysts
- Localized pain, tenderness & swelling
- Limp if wt bearing bone is affected
- Lesions in spine = neuro s/s
- Lesions at growth plate = stunt growth
XR shows:
* Aggressive, expansile, lytic metaphyseal lesion with sharp borders
* “Eggshell” sclerotic rim
* “Soap bubble”
dx?
aneurysmal bone cysts
tx for aneurysmal bone cysts
-
Excision, curettage & bone grafting
- Adjuvant chemical cauterization or cryotherapy -
Selective arterial embolization before surgery
- angiography to locate feeding artery to cyst
- Insert object (spring/foam) into feeding artery to create an emboli
MC malignant bone tumor
Arise from an overgrowth of malignant osteoblasts
osteosarcoma
MC sites for osteosarcoma
metaphysis of long bones
- Distal femur
- Proximal tibia
- Proximal humerus
2 peaks in incidence of osteosarcoma?
- Early adolescents
- Adults over 65 y/o
RF for osteosarcoma
- h/io irradiation or chemotherapy
- Paget disease, fibrous dysplasia, and other benign bone lesions
- Genetic predisposition
s/s osteosarcoma
-
Pain & swelling - 1st and MC
- worsened w/ activity - Palpable mass
- Limping if in wt bearing area
- Limited ROM if located in the joint
- Systemic sx not present
XR findings of osteosarcoma
- Both osteolytic and/or osteoblastic lesions
- “moth eaten”
- tumor extends thru periosteum = spiculated reaction, “starburst”
- Codman’s Triangle → new bone formation at periosteum
what intervention is used for each lesion after osteosarcoma is identified on bone scan?
CT/MRI
- CT - best for defining bone destruction & the pattern of calcification
- MRI - better for defining intramedullary & soft tissue extension
tx osteosarcoma
- Refer
- Core needle or open bx
- Pre- and post-op chemo w/ limb sparing surgery
T/F: osteosarcomas are radioresistant
T
- A tumor arising from chondrocytes (cartilage producing cells)
- MC after 50 y/o
chondrosarcoma
MC sites for chondrosarcoma
- pelvic and shoulder girdle
- Other: diaphysis of long bones
- Rarely seen in the spine & craniofacial bones
RF for chondrosarcoma
- Questionable genetic component
- MC from normal cartilage cells but may also stem from previous benign bone or cartilage tumor
- Enchondromas
- Multiple osteochondromas
- Ollier Disease (Enchondromatosis) → a cluster of enchondromas that affect the hands
s/s of chondrosarcoma
- Deep, dull aching pain; progressive
- Worse at PM
- Neuro sx if compresses NV bundle - MC in pelvic lesions
- Limited ROM if near a joint
- Sx of pathologic fx
XR findings of chondrosarcoma?
- bony contour thinned & expanded
- Multiple surface erosions → “endosteal scalloping”
- Lesion > 5 cm
- chondrosarcoma MC mets to what part of the body?
- how to eval?
lungs - get CT w/ contrast
tx chondrosarcoma
- Refer
- Surgical excision
A rare, peripheral primitive neuroectodermal tumor that can proliferate in the bone and/or soft tissue
Ewing sarcoma
cause of Ewing sarcoma
translocation between chromosomes 11 and 22
MC sites for ewing sarcoma
pelvis and femur
s/s of ewing sarcoma
- Localized pain & swelling; worse at PM or w/ activity
- Palpable mass
- Neuro deficits if compression of spinal cord or peripheral nerve
- constitutional sx = mets (F, fatigue, wt loss, anorexia)
XR findings of ewing sarcoma
- Poorly marginated destructive lesion
- “Onion skin” appearance - Due to a periosteal reaction
tx for ewing sarcoma
-
Multi-drug chemo w/ surgery +/- radiation
- Radiation if full resection of tumor is not possible
MC metastasizing cancers
- Breast
- Lung
- Thyroid
- Kidney
- Prostate
s/s mets bone disease
- Pain over metastatic location
- pathologic fx
- Anemia
w/u for mets bone disease
- XR - 1st
- Bone scans
- PET scans
- MRI
- Bx - definitive dx & determine primary site
tx for mets bone disease
- radiation + pain medication
- Chemo
- Bisphosphonates
- Surgery if inc risk for fx
