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Primary bone tumor
- Common <30 yr
- common around knee, humerous
- can arise any cell in bone-marrow 40%, osteoblast 19%, osteoclast 10%, carilage 22%, fibroblast
- most common site-prox femur, distal tibia, prox humerous
- young: benign=ostechchrondroma, malig=osteosarcoma
- older: benign-osteoma, malig-mult myeloma
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Secondary tumors
- MORE COMMON THAN PRIMARY
- PTBLK- prostate-blast, thyroid, breast-blast, lung, kidney
- kids: neuroblastoama, rhabdomyosarcoma, retinoblastoma
- mult lesion, or history of cancer=mets
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Clinical
- Benign= ASx/ indicental
- pain-nonspecific but sometimes helpful, typically deep, contant, worse at night, wks to months
- mass complicated by a pathologic fracture, growing lesion, significan ST rxn
- swelling-usu late or large tumor, may signify ST involvement
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Radiographic evaluation
- Plan XR= usually first imaging, can predict probable histology
- CT- useful when plain film is difficult due to anatomic site
- MRI- choice for local staging and surgery planning NOT Dx
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Biopsy
- May or may not be needed
- need enough tissue to Dx and grade
- Hx of Multiple Myeloma or prior cancer w/mult bony lesion
- ultimate Dx of bone tumor require radio-histo correlation
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Benign primary tumors
- Not all are neoplastic-hamartomas, disordered growth, often incidental, XR usually pathognomic
- osteochroma, osteoid oseoma, endochromcoma, fibrous, dysplasia, giant cell tumor of bone, aneursymal bone cyst, non—ossyfying fibroma, eosinophicli granuloma
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Benign Primary Tumor Tx
conservative
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Osteochondroma
- Most common benign
- mushroom shaped, bone w/cartilage cap
- located at epiphyseal line
- grows w/puberty, stop after plate close
- usually solitary
- mult- humt hereditary exostosis syndrom
- Tx: excision at base if Sx
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Osteoid osteom
- Reactive, very rare
- <20 y.o.
- deep seeded bone pain, VERY sensitive to NSAIDS-PGE2 release
- like diaphysis of long bones
- small tumor focus=nidus causes abundant reactive bone formation
- Tx: conservative, RFA-ablation
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Chondroma
- Childhood, persist throughout life-remnants of cartilage that failed to ossify in growth
- junction of diaphysis and metaphysis in long bones or short tubular bones of HAND & FOOT
- collection of benign hyaline cartilage
- often incidental
- usually solitary
- syndrome-olliers, affucci
- Tx: conservative
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Fibrous dysplasia
- Development abnormality-failure of primitive bone to align along stress lines-weaker bone susceptible to deformatives/fractures
- usually <30 y.o.
- prox femur, jaws, ribs
- ground glass
- mono or polyosticic
- McCune-albright synd
- histo: Chinese letter-irreg bone trabeulae, in fibrous stroma
- Tx: conservative
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McCune-Albright
Polyostic fibrous dyplasia, café au lait, endocrine abnormalities esp precocious puberty
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Giant cell tumor
- Young pts
- like epiphysis of long bones or vertebral bodies
- knee pain, ABC change or pathologic fracture
- radiology: soap bubble lesion-multicystic w/sclerotic rim, crosses epiphyseal line
- Tx: curettage-high recurrece rate, joint replacement if gets into space
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Aneurismal bone cyst
Unknown cause-primary of secondary
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Non-ossifying fibroma
- Metaphyseal fibrous defect
- common-most incidental finding
- error remodeling metaphyseal corticies in growth
- eccentric lesion in metaphyseal cortex or prox/distal tibia and fibula
- round or oval defects w/sclerolitc rim
- Histo: swirling of bland spindle cells w/admixed osteoclasts
- Tx: reassurance
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Langerhand cell histiocytosis
- Eosinophilic granuloma
- tumor of langerhan cells-related to macrophages
- occurs in mult organs, bone in kids
- usually incidental, may have mild pain or fracture
- great radiology imitator-looks like malignant esp ES/PNET
- Tx: observation, biopsy usually curative, low dose radiation
- CD-CD1a, S100+
- EM: berbeck granules
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LCH variants
- Hand-schuller Christian: (unisystem multifocal- exophtalmus, diabetes insipidus, lytic skull lesion)
- letterer-siwer: multisystem multifocal- young infants/toddlers, nearly always fatal
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Osteosarcoma
- Tumor of osteoblasts-tumor osteoid
- most common primary bone malig in kids
- may be primary or secondary
- secondary- ADULTS, arises in pagetic bone, radiated bone-esp w/alkylating agents
- distal femur, prox tibia, prox humerus, usu in metaphysis, usually unifocal, 20% have mets at presentation
- clinical- pain, soft tissue mass for months, pathological fracture
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Ostesarc dx
- Radiology- aggressive, usu radiodense lesion=osteoid
- periosteal reaction- not specific response to insult, codman’s triangle, sunburnt pattern
- seen in lesion that rapidly grow- periosteum can’t lay down new bone fast enough to form organized cortex and ossifies irreg
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Osteosarc gross
- Gritty and calcified
- destruction of bony arch
- usually involves surrounding tissue
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Osteosarc histo
- Atypical spindle cells that produce abnormal woven osteoid
- osteoid in ST lesion is definitioal of osteosarc
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Osteosarc variants
Conventional 80%, periosteal, chondroblastic, periosteal, telangectasic, small cell, dediff
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Osteosarc Tx
- Xray and incisional Bx for dx w/MRI
- Neoadjuvant chemo and repeat MRI, then resection w/wide margins-limb salvage better
- poor prog: <90% tumor response, large, adult or secondary, axial skeletal site
- 5 yr survival 70%
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Chondrosarcoma
- Malig tumor of chrondrocytes
- older pts than Osteosarcoma-30-60 yr
- usually large tumor at Dx
- most common in trunk/ prox limgs
- pelvis, shoulder, prox humerus/femur-trunk and prox limbs
- Xray: stippled/popcorn caliciction w/ST involvement
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Chondrsarcoma gross/hist
- Lobular tumor w/firm grayish cartilage-NO OSTEOID
- hyaline cartilage but more cellular w/atypia
- grade important for prognosis
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Chondosarcoma Tx
- Varies
- tx: surgery-chondrocyte don’t respond well to chemo
- prognosis highly dep on grade
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Ewing sarcoma/primitive neuroectoderm
- SRBCT
- 2nd and 3rd decades
- pelvis, LE, spine
- Askin tumor: ES/PNET involving rib
- diaphysis
- Histo: can see pseudorosettes w/neuritic processes in center
- CD99 pos
- translocation: t(11;22)
- Tx: neoadjuvant chemo and surgery
- 5 yr survival 65%
- radiation for close margins
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