Bone Tumor NM + pictures Flashcards
(44 cards)
Osteosarcoma
painful mass rising at metaphyseal regions
most common knee (the end of long bones)
Conventional type 80% – 10-20 years
Parosteal sarcoma – posterior distal metaphysis of femur
Osteosarcoma T
T1 < 8 cm long
T2 > 8 cm long
T3 2 lesions in one bone
Osteosarcoma risk
Polyostotic Paget long term – secondary
Previous radio
Familial retinoblastoma
Rothmund-Thomson sy (skin)
Bone infarct
Osteosarcoma M
lung
bone
LN
Osteosarcoma X-ray
Medullary and cortical bone destruction, wide zone of transition (permeative or moth-eaten appearance), aggressive periosteal reaction
Osteosarcoma CT
Staging, lytic lesions
Chest – MTS
Osteoid matrix – cloud like, poorly defined
Cartilage matrix – dots, rings, arcs of calcification <2mm
Osteosarcoma MRI
Joint-to-joint
Assessment of growth plate – 75-88% cross growth plate to epiphysis
Osteosarcoma NM
Bone scan: 3-phase positive, extent of osseous diffusion, level of bone resection
FDG: high grade intense uptake – tumor-to-background ratio cutoff 3.0 for malignant lesion
Tl, MIBI, Fluoride
SUV <2 after therapy – good response
SUV >5 – poor response
Osteosarcoma therapy
Effective neoadjuvant – less amputation – active ossification mimics therapy failure – SUV <2.5 post therapy predicts tumor necrosis
Enlarge on posttherapy image
Osteoid osteoma
Benign
Pain at night
Cortex of long bones (50% femur or tibia)
Intracortical <2cm nidus + mineralization, cortical thickening, reactive sclerosis
Osteoblastoma
Benign
Posterior element of spine (cervical)
Nidus >2cm
Greater potential for growth, bone destruction, malignant transformation, recurs
OO NM
Bone scan: lucent nidus surrounded by sclerosis – very hot spot + surrounding diffuse mildly increased uptake
SPECT - “one stop shop”
FDG – response to treatment
Ewing Sarcoma
4-15 years
Pretreatment high SUV – high grade
SUV >5.8 – poor prognosis
Post-neoadjuvant SUV <2.5 – good response (90% necrosis)
Ewing sarcoma Prognostic factor
size of lesion and distant MTS
Ewing Sarcoma NM
diaphysis of long bone (femur)
Bone scan: nonspecific increased uptake
FDG: >MRI in skip lesions, MTS LN
< chest CT
Chondroma
Benign, 30-80 years
Compose of mature hyaline cartilage – limited growth potential, not aggressive
Enchondroma
occur in medullary canal
melting sore at pressure
20-30 years
>6cm – high risk for chondrosarcoma
Risk for chondrosarcoma
Ollier disease
Mafucci disease
Exostosis
Most likely to seed biopsy track
Chondroma CT
Cartilaginous matrix, endosteal scalloping
Thickness of cap >2cm – malignant
Chondroma NM
Bone scan: cartilage matrix with increased uptake – malignant
FDG: low SUV for benign
SUV >2 threshold for malignant
No radio, no chemo
Osteoid osteoma
Osteosarcoma
Chondrosarcoma
Ewing sarcoma
