MSK TUMORS Flashcards
BENIGN BONE LESIONS
Well defined Narrow zone of transition No cortical destruction Confined within the bone No soft tissue reaction
AGGRESSIVE/MALIGNANT FEATURES
Ill-defined border Wide zone of transition Large lesion Not confined by natural barriers Growth plate, cortex Cortical destruction / fracture Soft tissue involvement
Ill- defined Wide zone of transition Cortical destruction Not confined within the bone Soft tissue reaction
BIOPSY TYPE
Provides cytologic (cellular) specimen only
Frequently used for carcinoma
Not used for sarcomas
FNA
BIOPSY TYPE
Allows for tumor structural examination
Cytologic and stromal elements
Frequently used for sarcomas
core biopsy
OSTEOID OSTEOMA
benign bone tumor
usually in lower extremities
Nidus = Central nodule with osteoblastic rim
Reactive zone = Area of thickened bone
Pain= Increased local concentration of prostaglandin E2 and COX 1&2 expression = which is why NSAIDS HELP!!!!
PAIN = constant & progressive
- pain is worse at night and after drinking alcohol
TREATMENT = NSAIDS!!!! - and observation
- can ablate or surgical resection with curettage
osteoid osteoma imaging
if < 1.5 cm = osteoid osteoma
if > 1.5 cm = osteoblastoma
Radiographs
2-3 views of the affected bone or joint
Intensively reactive bone around radiolucent nidus
CT
Helps to identify size and location of the nidus
osteoid osteoma Nidus <1.5cm
(osteoblastoma – nidus >1.5cm)
Bone scan
Hot area at the nidus
MRI
Usually not indicated
PROGNOSIS OF OSTEOID OSTEOMA
Pain from lesion usually resolves after ~ 3 years
Lesion spontaneously resolves in 5-7 years
In the spine early resection (within 18 months) leads to resolution of scoliosis in children <11 years
OSTEOSARCOMA
Most common primary sarcoma of bone
Usually occurs in children and young adults
Majority occur during the second decade of life
Can occur in the elderly and is associated with Paget’s disease
Most common site – DISTAL FEMUR
Other common sites – proximal humerus, proximal femur, pelvis
10-20% of patients will present with pulmonary metastases
Associated with the RETINOBLASTOMA TUMOR SUPPRESSOR gene (Rb)
MOST COMMON SIGHT FOR OSTEOSARCOMA
distal femur
what gene is osteosarcoma associated with
RETINOBLASTOMA TUMOR SUPPRESSOR gene (Rb)
also associated with Paget’s disease
and pulmonary mets
osteosarcoma symptoms & prognosis
Rapidly progressive painful mass
Prognosis
76% long-term survival with modern treatment
POOR PROGNOSTIC FACTORS Advanced stage of disease Poor response to chemotherapy Large tumor size Pelvic location Skip lesions High serum ALP, LDH Vascular involvement
osteosarcoma requires CT of chest?
to assess for pulmonary mets
OSTEOSARCOMA IMAGING
Radiographs
Characteristic blastic and destructive lesion
Sun burst or hair on end periosteal reaction
Codman’s triangle periosteal reaction
Large soft tissue mass
MRI
Soft tissue involvement
May see neurovascular involvement
Assesses for skip lesions
Bone scan
Hot
CT Chest
Required to look for pulmonary metastases
OSTEOSARCOMA TREATMENT
chemo, then surgical resection
may need amputation (if pathologic fracture, vascular involvement, or progression of tumor despite chemo)
ENCHONDROMA
A benign chondrogenic tumor composed of hyaline cartilage
Located in the medullary cavity
Caused by an abnormality of chondroblast function in the physis
Chondroblasts and fragments of epiphyseal cartilage escape from the physis into the metaphysis and proliferate there
Second most common benign cartilage lesion
1% chance of enchondroma transforming into
chondrosarcoma (malignant)
most common location for enchondroma
HANDS
location: Diaphyseal or metaphyseal medullary cavity
SYMPTOMS OF ENCHONDROMA
Often asymptomatic and discovered incidentally
Especially in long bone and foot enchondromas
Pathologic fracture
Hand enchondromas
Pain = uncommon
endochondroma imaging
in hand = appear more lytic
but in other locations = more popcorn stippling appearance
XRAY
Well defined, lucent, central medullary lesions that calcify over time
1-10cm in size
Appear in the metaphysis but become diaphyseal as the long bone grows
Popcorn stippling, arcs, whorls, rings
May be purely lytic in the hands
Minimal endosteal erosion
May see cortical expansion in the hands and feet
CT, bone scan, MRI
Usually not indicated
TREATMENT FOR ENDOCHONDROMA
- observation
- intralesional curettage & bone grafting
- if pathologic fractures in hand = immobilization till healed, then intralesional curettage & bone grafting
MOST COMMON BENIGN TUMOR OVERALL
OSTEOCHONDROMA
OSTEOCHONDROMA
MOST COMMON BENIGN BONE TUMOR OVERALL
Chondrogenic lesion derived from aberrant cartilage from the perichondral ring
Cartilaginous cap with varying amounts of ossification and calcification
True incidence is unknown as many are asymptomatic
Common in adolescents and young adults
occur at the surface of the bone
MOST COMMON LOCATION FOR OSTEOCHONDROMA
around the knee - proximal tibia, distal femur
osteochondroma prognosis
Risk of malignant transformation
<1% with solitary osteochondroma
5-10% with multiple lesions
secondary chondrosarcoma
Malignant transformation of osteochondroma
Usually low grade
Occurs in older patients
Most common location is the pelvis
Malignant transformation of osteochondroma
secondary chondrosarcoma
must common location = pelvis
Disorder characterized by multiple osteochondromas
Multiple Hereditary Exostosis (MHE)
Autosomal dominant inheritance
Mutation in EXT1, EXT2, and EXT3 genes
Higher risk of malignant transformation
SYMPTOMS / PHYSICAL EXAM OF OSTEOCHONDROMA
Most lesions are asymptomatic
Usually present with painless mass
May have mechanical symptoms or symptoms of neurovascular compromise
Continue to grow until skeletal maturity
Acute onset of pain should raise suspicion for malignancy
Physical exam
Palpable mass
Firm, non-tender, and non-mobile
osteochondroma imaging
XRAY
- can be sessile (within) or pedunculated
- high risk of malignant transformation in sessile
Always point away from the joint
Cortex and medullary cavity of lesion is continuous with the cortex and medullary cavity of native bone
Cartilage cap is radiolucent
may use CT/MRI for better distinction
osteochondroma treatment
Observation = Asymptomatic lesions
Marginal resection at base of stalk including cartilage cap = Symptomatic lesions
Recurrence – 2-5%
CHONDROSARCOMA
Malignant primary bone tumor composed of chondrocytes
PRIMARY CHONDROSARCOMA
Low grade, high grade, dedifferentiated
Clear cell chondrosarcoma
Mesenchymal chondrosarcoma
SECONDARY CHONDROSARCOMA
Arises from benign cartilage lesions
Osteochondroma, multiple hereditary exostosis, enchondromas
Poor prognosis with axial and proximal extremity lesion and higher grade tumors
most common location of chondrosarcoma
PELVIS
symptoms of chondrosarcoma
PAIN is most common symptom
Variable rate of presentation dependent on tumor grade and location
Pelvic masses - may present with slowly growing mass of symptoms of bladder/bowel obstruction due to mass effect
Pathologic fracture
chondrosarcoma imaging
XRAYS
Lytic or blastic lesion with reactive thickening of the cortex
Vast majority have significant cortical changes
Intralesional “popcorn” mineralization
More prevalent as the lesion ages
MRI
Helpful to determine marrow and soft-tissue involvement
CT
Helpful to assess cortical involvement
Bone Scan
Can determine location of metastatic disease
Chondrosarcoma itself is hot
chondrosarcoma treatment
Generally RESISTANT to chemotherapy and radiation
Intralesional curettage = Low grade lesions
WIDE SURGICAL EXCISION** = Most commonly performed
chondrosarcomas are generally resistant to chemo and radiation, so most common treatment =
wide surgical excision
NON-OSSIFYING FIBROMA
most common benign tumor in childhood
Related to dysfunctional ossification
Metaphysis of long bones
80% in the lower extremity
Distal femur > proximal tibia > proximal fibula > distal tibia
most common benign tumor in childhood
non-ossifying fibroma
symptoms of non-ossifying fibroma
ASYMPTOMATIC
Found incidentally
Painless
May present with pathologic fracture
imaging of non-ossifying fibroma
Diagnostic
Metaphyseal eccentric “bubbly” lytic lesion with surrounding sclerotic rim
Cortex may be expanded and thin
As bone grows lesion enlarge and migrate into the diaphysis
Become sclerotic as patient reaches skeletal maturity
non-ossifying fibroma treatment
most resolve on their own
1st line = non-operative
Operative = curettage & bone grafting
UNICAMERAL BONE CYST
BENIGN
Serous filled lesion thought to result from temporary failure of medullary bone formation near the physis
Usually found in patients <20 years old
Proximal humerus and proximal femur most common
Arises in the metaphysis adjacent to the physis
Progresses towards the diaphysis with bone growth
most common locations for unicameral bone cysts
near physis
proximal humerus, proximal femur
prognosis of unicameral bone cyst
Often decrease in size and may heal as growth is complete
Fracture healing may lead to cyst resolution
Pathologic fracture may lead to growth arrest
active vs latent unicameral bone cyst
Active = Cyst adjacent to the physis
Latent = If normal bone separates cyst from the physis
unicameral bone cyst symptoms
Usually asymptomatic
Pain with pathologic fracture
From minor trauma
~50% of patients present with pathologic fracture
fallen leaf sign
unicameral bone cyst
Pathologic fracture with fallen cortical fragment in base of the cyst
unicameral bone cyst treatment
observe asymptomatic lesions - immobilization of pathologic fractures
- aspiration / methylprednisolone injection
operative = curettage & bone grafting
ANEURYSMAL BONE CYST
Benign reactive bone lesion
Filled with multiple blood filled cavities
Can be locally destructive to normal bone
Can extend to soft tissues
Vast majority of patients are < 20 years
Associated with other tumors 30% of the time Giant cell tumor Chondroblastoma Fibrous dysplasia Chondromyxoid fibroma Non-ossifying fibroma
location = spine or long bones (metaphysis)
ASSOCIATED WITH OTHER TUMORS
ANEURYSMAL BONE CYST
location of aneurysmal bone cysts
metaphysis - spine or long bones
symptoms of aneurysmal bone cysts
Pain and swelling
Pathologic fracture
Neurologic deficits possible with spine lesions
imaging of aneurysmal bone cysts
Radiographs Expansile, eccentric, lytic lesion Bony septae – bubbly appearance Usually metaphyseal Thin rim of periosteal new bone
MRI and CT Scan
Multiple fluid lines*** within cyst
May show soft tissue involvement
TREATMENT OF ANEURYSMAL BONE CYST
Non-operative = Asymptomatic lesion
Pathologic fracture - May lead to spontaneous resolution
Operative Aggressive curettage and bone grafting Symptomatic lesions with no fracture \+/- phenol, argon beam, liquid nitrogen Recurrence up to 25%
EWING’S SARCOMA
Second most common malignant bone tumor in children
Distinctive small round cell sarcoma
Typically found in patients from 5-25 years of age
Location
~50% are found in the diaphysis of long bones
Pelvis, femoral diaphysis, distal femur, proximal tibia, proximal humerus
Genetics T(11:22) translocation - Found in 95% of cases
prognosis: spine/pelvic tumors < proximal extremities < distal extremities
T(11:22) translocation
ewing’s sarcoma
biggest symptoms of ewing’s sarcoma
FEVER
EWING’S SARCOMA SYMPTOMS
Pain FEVER Often mimics infection Swelling Local tenderness
imaging of ewing’s sarcoma
Image entire bone
Large destructive lesion in the diaphysis or metaphysis with a permeative moth-eaten appearance
Lesion may be purely lytic or have variable amounts of reactive new bone formation
Periosteal reaction = Onion skin or sunburst appearance
which 2 need a chest ct to look for pulmonary mets
Osteosarcoma
Ewing’s sarcoma
LABS FOR EWING’S SARCOMA
ESR elevated
WBC elevated
Anemia
LDH elevated
**Bone marrow biopsy = required to rule out mets to bone marrow
treatment for ewing’s sarcoma
chemo + radiation for nonresectable
resectable = chemo + limb salvage resection + radiation
MULTIPLE MYELOMA
MOST COMMON PRIMARY BONE MALIGNANCY
Neoplastic proliferation of plasma cells
Presents with skeletal lesion
Plasma cells produce immunoglobulins
IgG, IgA, IgM
Patients > 40 years of age
Males > females
2x as common in African-Americans
CLINICAL FEATURES OF MM (CRAB)
hypercalcemia
renal insufficiency
anemia
bone lesions
symptoms =
Localized bone pain - Spine or ribs
Pathologic fracture
Fatigue - Secondary to anemia, renal insufficiency, hypercalcemia
imaging for MM
won’t show up in bone scan**
Radiographs
Multiple “punched-out” lytic lesions
Caused by osteoclastic bone resorption
MRI
Better for pelvis and spine lesions
PET scan
93% sensitive
An emerging gold standard
LABS FOR MM
Anemia
Elevated creatinine
Hypercalcemia - Excessive bone resorption
Elevated ESR
Serum protein electrophoresis (SPEP) - M spike - Abnormal immunoglobulin production
Proteinuria
Urine protein electrophoresis
May show Bence Jones proteins (secreted light chain immunoglobulins)
mainstay of treatment for MM
multi-agent chemotherapy***
other treatment = stem cell, bisphosphonates
operative
METS - BONE LESIONS
BONE = 3RD MOST COMMON SITE OF METS
- after lung & liver
Carcinomas that commonly spread to bone: Breast Lung Thyroid Renal Prostate
Prognosis
Lung > kidney > breast > prostate > thyroid
most common site for METS
SPINE - THORACIC SPINE
also common = proximal femur
symptoms of METS
Pain
- Mechanical due to bone destruction
- Night time pain
Pathologic fracture
Neurologic deficits - Spinal cord compression with metastatic disease in the spine
Metastatic hypercalcemia
- Confusion
- Muscle weakness
- Polyuria/polydipsia
- Nausea/vomiting
- Dehydration
work up for mets
Plain radiographs of the affected limb
CT chest/abdomen/pelvis
Bone scan
Skeletal survey
Obtain in suspected myeloma and thyroid carcinoma only
Labs
CBC w/ diff, ESR, BMP, LFT’s, Ca, Phos, ALP
SPEP and UPEP
Biopsy
Indicated when a primary carcinoma is not identified on above work-up
METS TREATMENT
Based on primary carcinoma
NON-OPERATIVE Bisphosphonate therapy Prevents osteoclastic bone destruction Chemotherapy Radiation Hormone therapy
OR OPERATIVE
PREOP EMBOLIZATION = if thyroid or renal mets (very vascular)
lipoma
Mineralization / calcification is worrisome for synovial cell sarcoma
associated conditions for ganglion
Median or ulnar nerve compression
Volar ganglion
Hand ischemia due to vascular occlusion
Volar ganglion
most common location for ganglion cyst = hand - dorsal hand
1st line treatment for ganglion cyst
observation
aspiration = 2nd line tx
