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Flashcards in Unknown origin tumours Deck (32):

Describe metastatic cancer of bone?

  • The commonest reason for a destructive bone lesion in adults
  • cancers that spread to bone
    • breast
    • Lung
    • thyroid
    • renal
    • prostate
  • ​Boneris 3rd commonest for metastatic disease ( after lung, liver)
  • usually >40 yrs
  • common sites
    • axial skeleton- thoracic spine most common site
    • proximal limb girdle
    • prox femur most common site of fx 2ary to met bone lesion


What is the pathophysiology of bony mets?

  • Mechanism of osteolysis
    • osteolytic bone lesions - caused by Tumour induced activation of osteoclasts
      • occurs thru RANK, RANKL, osteoprotegrin
    • Osteoblastic bone mets are due to tumour secreted endothelin 1


What is the prognosis of pts with metastatic disease with thyroid, prostate, breast, kidney and lung?

  • Thyroid 48 months
  • Prostate 40 months
  • Breast 24 months
  • Kidney variable short as 6 months
  • Lung : 6 months


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Name associated conditions of metastatic disease?

  • Metastatic hypercalaemia
    • medical emergency
      • confusion
      • muscle weakness
      • polyuria/polydipsia
      • nausea/vomiting
      • dehydration
    • tx with hydration and loop diuretics


describe the mechanism of metastasis?

  • Tumour cell intravasation
    • E cadherin cell adhesion molecule on tumour cells modulates release from primary tumour focus into bloodstream
  • Avoidance of immune surveillance
  • target tissue localization
  • induction of angiogenesis - via vascular endothelial growth factor (VEGF) expression
  • genomic instability
  • decreased apoptosis
  • Vascular spread
    • Batson's vertebral plexus
    • valveless venous plexus of the spine that provides a route of metastasis from organs to axial structure including vertebral bodies, pelvis, skull and prox limb girdles
    • Arterial tree metastasis
      • ​mechanism which lung/renal cancer spreads to distal extremities

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What are the symptoms of metastatic disease?

  • Pain
    • mechanical due to bone destruction or tumorigenic pain at night
    • Pathological Fx 8-30%
    • metastatic hypercalcaemia
  • ​O/E
    • Neurological deficit
      • compression of spinal cord with mets disease to spine


Describe the workup for a pt with suspected metastatic diseasee?

  • Plain radiographs
    • ​lung, thyroid & renal = lytic
    • 60% breast ca= blastic
    • 90% prostatic ca= blastic
    • lesions distal to elbow/knee often lung/renal primary- see pic
  • CT chest /adbo/Pelvis
  • Technetium bone scan- to detect extent of disease
    • myeloma & thyroid ca are cold
    • elevate with skeletal survey if cold
  • Labs
    • U&E
    • ESR
    • LFT's, CA, Phos, Alk Phosphatase
    • serum & urine immunoelectrophoresis
  • Biopsy
    • shouldn't tx bone lesion without tissue dx

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What is the goal of tx in metastatic disease?

  • Control pain 
  • Maintainence of patient independence


What is the tx of metastatic disease?

Non operative

  • Bisphosphonates
    • symptomatic to prevent osteclastic bone destruction
    • iv pamidronate most commonly used


  • Stabilisation of complete fx, postop radiation
    • most complete fx are treated if op stabilisatio leads to improved quality of life
    • post op radiation
      • all pts unless death immunent or area has had previous radiation
      • begin radiation after surgery
      • area of irradiation should include entire fixation device
  • ​​Prophylatic stabilisation of impeding fx ( entire bone - ie nail) allow immediate WB, post op rdx
  • preop embolization
    • ​renal cell carcinoma/thyroid as v vascular


What is the tx for metastatic spinal lesion?

Non operative

  • Palliative care
    • if life expectancy< 6months


  • Neurological decompression, spinal stabilisation adn post op radiotherapy
    • for met lesions to spine with neurological deficits in pts with life expectancy > 6 months
    • preop embolisation included for renal ca to psine


Are there any scoring systems to help decide prognosis of  spinal mets and so tx?

  • Tokuhashi et al Spine 2009. published a scoring system to help develop a treatment algorithm for patients with metastatic spinal lesions.
  • They used a patient's

    • general condition

    • number of extraspinal bone metastases

    • the number of metastases in the vertebral body,

    • the metastases to other major internal organs,

    • the primary site of the tumor,

    • degree of neurologic compromise to determine the life expectancy.

    • They recommended against surgical intervention for patients with less than six months to live.


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What is a Giant cell tumour?

  • A Benign Agressive Tumour
  • typically found in Epiphysis of long bones but may airse in apophysis ( like chondroblastomas)
  • > females (cf most bone tumours)
  • Age 30-50 yrs
  • location
    • 50% around knee
    • **10% sacrum/vertebra body**
    • distal radius
    • phalanges also common
    • may a

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Describe the malignancy of gct?

  • Primary malignant giant cell tumour
    • mets to lung in 2-5%
    • hand lesions have > chance of metastasis
  • ​Secondary malignant giant cell tumour
    • ​occurs following radiation/multiple resections of GCT


What are the symptoms of GCT?

  • Pain refered to involved joint


  • palpable mass
  • decreased rom of joint


What is seen on imaging a GCT?


  • An Eccentric Lytic Epiphyseal/Metaphsyeal lesion
  • often extends into the distal epiphysis and borders subchondral bone

Bone scan

  • Very hot


  • Demarcation on T1 image between fatty marrow and tumour- see pic

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Describe the histology of GCT?

  • Neoplastic cell is the mononuclear stromal cell- see pic
  • Hallmark giant cells are numerous
  • secondary aneurysmal bone cysts not unusual

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What is the tx of GCT?

Non operative

  • Radiation alone
    • only inoperable/multiple lesions
    • 15%-> malignant transformation
  • Medical Mx
    • Bisphosphonates
      • OC inhibitors- may decrease size of defect in GCT
    • Denosumab
      • Monoclonal antibody against RANKL
      • trails= decrease size of defect in GCT


  • Extensive Currettage and Reconstruction ( w adj tx)
    • lesions amenable to currettage
    • hand lesions controversial
      • if no cortical defect- currettage + cement
      • if cortical defect- intercalary resection w fibular free graft vs amputation
      • need to preform extensive exterioration ( removal of large cortical window over lesion ) is required
    • Outcome 10-30% recurrence vs 3% w adjuvant tx ( phenol, hydrogen peroxide)


What is Ewing's sarcoma?

  • A distinctive  round cell bone sarcoma
  • 5-25 yrs
  • 2nd most common bone tumour in children
  • Uncommon in african americans/chinese
  • 50% Diaphysis of long bones
  • locations
    • Pelvis, distal femur, proximal tibia, femoral diaphysis, proximal humerus
  • Genetics
    • t( 11:22) translocation - in all cases
    • which leads to -> Fusion protein ESW-FLI1= identified w PCR

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What is the prognosis of Ewing's sarcoma?

  • 60-70% long term survival w isolated extremity disease 
  • 40% long term survival w pelvic lesions
  • 15% long term survival if presents w mets

Poor prognostic factors

  • Spine & pelvic tumours
  • tumour >100cm3
  • <90% necrosis w chemo
  • elevated lactic dehydrogenase levels
  • p53 mutation in addition to T(11:22) translocation


What is the symptoms of Ewing's sarcoma?

  • Pain accompanied by fever
  • often mimics infection


  • Swelling and local tenderness

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What are the signs of Ewing's sarcoma on imaging?


  • Large destructive lesion in Diaphysis/metaphysis with a Moth eaten appearance- see pic
  • Lesion maybe purely lytic or somereactive bone formation
  • Periosteal reaction= onion skin/sunburst appearance

Bone Scan

  • Hot lesion


  • often shows large soft tissue component

CT chest

  • Bony Mets

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What is seen on lab results with Ewing's sarcoma?

  • Elevated WCC
  • Elevated ESR
  • Anaemia Common
  • Lactic Dehydrogenase
  • Bone marrow biopsy- to rule out mets in marrow


What is seen on histology with Ewing's sarcoma?

  • Gross- may have liquid consitency like pus
  • sheets of monotomous small round blue cells- see pic
  • prominent nuclei and minimal cytoplasm
  • may have pseudo-rosettes ( circle cells w necrosis in centre)
  • Immunostaining
    • CD99 reactivity

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Describe the tx for ewing's sarcoma?

  • Operative
    • Chemotherapy and Limb Salvage Resection
      • standard most pts
      • preop chemo 8-12 wks then surgery then chemo 6-12 mo post 
      • Curent trend away radiotx
      • only with resectable tumours/mets


What are the age differentials of small- round cell tumours?

  • <5 yrs= Neuroblastoma/ Leukaemia
  • 5-10 yrs= Esosinophilic Granuloma
  • 5-30 yrs= Ewing's sarcoma
  • >30 yrs= lymphoma
  • >50 yrs= myeloma


What is an Adamantioma?

  • A rare low grade Malignant tumour of unknown aetiology that is almost always located in the mid-tibia
  • <300 cases documented
  • young adults 20-40 yrs

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Name associated conditions of adamantinoma?

  • Osteofibrous dysplasia
    • not a precusor of adamantinoma
    • a BENIGN, fibro-osseous lesion in the tibia cortex of young children
    • Tx by observation

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What is the prognosis of adamantinoma?

  • May metastatize to lungs 25%
  • so longterm follow up is recommended
  • reocurrance is uncommon with negative margin excision


What are the symptoms of adamantinoma?

  • Pain of months- years duration


  • Bowing deformity of tibia
  • Palpable mass of tibia

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What is seen on imaging of adamantinoma?

  • xray
    • Multiple sharply circumscribed lucent lesions "soapy bubbles" with interspersed sclerotic bone in mid tibia
    • some lesions mat destroy cortex
    • may see bowing of tibia
    • radiographic evolution of lesion helpful as lesions may continue to grow and erode cortex
    • No periosteal reaction

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What is seen in histology of adamantiomas?

  • Fibrous and epithelial tissue in gland like pattern
  • nests of epithelial like cells arranged in palisaing or glandular pattern
  • background of stroma


What is the tx of adamatiomas?

  • Operative
  • Wide margin surgical resection
    • most pts
    • often requires intercallary resection w allograft /megaprosthesis reconstruction
    • Chemo and Radiotx typically not used