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Flashcards in Osteogenic tumours Deck (44):

What is osteoid osteoma?

  • A self limiting BENIGN bone lesion usually younger pts
    • presents with pain unrelated to activity


What is the epidemiology of  osteoid osteoma?

  • 5-30 years
  • Mostly in 2nd decade of life
  • 2:1 male/f ration
  • location
    • 50% in Diaphysis/Metaphysis of long bones of lower extremity
    • Prox femur>tibia diaphysis?post elements spine>fingers>feet
    • most common in prox femur
    • Most common intra-articular Hip joint
    • most common in scaphoid/prox phalanx hand

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What is the pathoanatomy of  osteoid osteoma?

  • Thought to be from nerve fibres assoc with blood vessels within the nidus
  • Pain is 2ary to PROSTAGLANDIN secreation and COX1/2 expression


What are the assoc conditions of  osteoid osteoma?

  • Painful scoliosis
  • growth disturbance
  • flexion contractures

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What is the prognosis of  osteoid osteoma?

  • Pain from lesions usually Resolves after average 3 yrs
  • the lesion spontaneously resolves 5-7 years
  • In spine early resection within 18 months-> resolution of scoliosis in younger children <11 yrs


The posterior elements of the spine include?

  • pedicle
  • lamina
  • facet joint

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What are the symptoms and signs of osteoid osteoma?


  • Pain
    • increases w time
    • worse at night , w drinking etoh
    • Relieved by NSAIDS
    • may be adjacent to joint/mimic OA
  • ​hand lesion may pc- painless swellings


  • joint effusion
  • contractures
  • limp
  • muscle atrophy
  • painful nonstructural scoliosis
    • result of paravertebral spine
    •  osteoid osteoma is located on concave side of apex of curve



What is the typical view of osteoid osteoma on xray?

  •  intensely reactive bone around a Radiolucent nidus ( see pic)
    • Nidus is <1.5cm ( otherwise blastoma)
    • nidus maybe difficult to see on plam

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IS Ct useful in dx of osteoid osteoma?

  • Study of choice
  • to identify nidus surrounded by sclerotic rim

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What is seen on bone scan in osteoid osteoma?

  • Always hot
  • with intense focal uptake

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How is osteoid osteoma charatersized histologically?

  • Distinct demarcation between nidus and reactive bone
  • Nissud contains uniform osteoid seams of immature osteoid trabeculae ( woven bone) with a sharp border of osteoblastic rimming

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What is the difference between osteoid osteoma and osteoblastoma?

  • Osteiod osteoma <1.5cm Osteob >1.5cm
  • Site long bone diaphysis cf post elements of spine/long bone metaphysis for OB
  • Location
    • Prox femur>tibial diaphysis>spine- OSO
    • Spine>prox humerus>hip- OSTblastoma
  • Self limiting OSteo cf progressive with Osteob
  • Symptoms
    • nocturnal pain relief from nsaids- OO
    • dull ache , not relieved by nsaids- OB
  • MX
    • non surgical 1st, surgery 2nd- OO
    • Surgery always indicated in OB as don't repsond to nonsurgical


Tx of osteoid osteoma

  • Non operative
    • clinical observation & nsaids
  • Operative
    • percutaneous radiofrequency ablation
      • CI lesions close to spinal cord
      • under ct guidance
      • probe at 80-90oC for 6 mins to produce 1cm zone of necrosis
      • 90% success tx with 1-2 sessions
      • 10-15% recurrence rate
    • surgical resection
      • location of lesion not amenable to ablation
      • removal of osteoid oseotoma will allow resolution of scoliosis without further tx


What is osteoblastoma?

  • Agressive benign osteoblastic tumour
  • nidus >2cm

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What is the epidemiology of osteoblastoma?

  • Rare
  • less common than osteoid osteoma
  • males>females 2:1
  • majority pts 10-30 yrs
  • most common in posterior elements of spine
  • 10-40% assoc with 2ary aneurysmal bone cyst


what are the symptoms of osteoblastoma?

  • Pain
    • slow aggressive but dull
    • No relief from NSAIDS


What are the findings of osteoblastoma on xray?

  • Lytic or mixed lytic-blastic lesion with radiolucent nidus >2cm
  • reactive sclerotic bone

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What is seen on bone scan with osteoblastoma?

A hot intense focal lesion

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What is seen on histology of osteoblastoma?

  • Distinct demarcation between nidus and reactive bone
    • nidus of immature osteoid and osteoblasts with abundant cytoplasm and normal nuclei

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What is the Tx of osteoblastoma?

  • Observation
    • rarely indicated as lesion with continue to grow!!
  • Operative
  • Curettage or maginal excision with bone grafting
    • ​ standard of tx
    • reocurrence 10-20%


What is parosteal osteosarcoma?

  • A low grade osteosarcoma
  • > females age 30-40 yrs
  • location
    • on surface of metaphysis of long bone
    • posterior distal femur, prox tibia, prox humerus
    • 80% occur in femur

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What is the prognosis of parosteal osteosarcoma?

  • 95% long term survival when local control achieved
  • dedifferentation of parosteal ostoesarcoma is poor prognostic factor
  • invasion into medullary cavity doesn't effect long term survival

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What symptoms of parosteal osteosarcoma?

  • Painless mass

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What is seen on xrays of parosteal osteosarcoma?

  • heavily ossified, lobulated mass arising from cortex
  • appears stuck to cortex

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What is seen on histology of parosteal osteosarcoma?

  • low grade lesion
  • regularly arranged normal osseous trabeculae
  • atypical spindle cells seen between regularly arranged osseous trabeculae
  • histology can be mistaken for by Fibrous Dysplasia

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What is the tx of parosteal osteosarcoma?

  • Operative
  • Wide local excision
    • standard care in most pts
    • Chemo not indicated unless high grade component
    • curative outcome


What is intramedullary osteosarcoma?

  • Most Common Primary sarcoma of Bone
    • usually occurs in children/ young adults
  • majority occur 2nd decade of life
  • 2nd peak= elderly assoc with Pagets
  • Site
    • ​distal femur/ proximal tibia
  • commonly dx at Stage 2B (high grade/extracompartment, no mets)
  • 10-20% present with pulmonary mets
    • most common malignancy of bone = metastatic disease
    • most common primary malignancy of bone= myeloma

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Is there any genetics assoc with intramedullary  osteosarcoma?

  • Risk increased with Rothmund Thomson syndrome
  • Pts who carry Retinoblastoma tumour supressor gene are predisposed to osteosarcoma


What is the prognosis of intramedullary  osteosarcoma?

  • 76% long term survival w modern tx
  • poor prognsotic factors
    • adv stage of disease ( most predictive of survival)
    • response to chemotherapy ( judged by precent tumour necrosis of resected specimen)


What are the signs and symptoms of intramedullary  osteosarcoma?

  • Symptoms
    • progressive pain, fever & swelling
  • Signs
    • may feel mass on exam


What is seen on xray re intramedullary  osteosarcoma?

  • Blastic and destructive lesion
  • sun burst or hair on end appearance of matrix mineralisation
  • periosteal reaction- Codman triangle ( see pic)
  • large soft mass w maintence of bone cortices


  • useful to identify SKIP lesions- Mets
  • extent of neurovascular/soft tissue involvement
  • bone scan - very hot!!
  • NB CHEST CT - exlcude pulmonary mets

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what labs investigations are abnormal?

  • Elevated alkaline phosphatase

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What does histology show in intramedullary  osteosarcoma?

  • Tumour cells- atypia and produce a lacey osteoid
  • stroma cells show signs of atypia, high nuclear to cytoplasmic ratio and abnormal mitotic figures

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What is the tx for intramedullary  osteosarcoma?

  • Multiagent chemotherapy and limb salvage resection
    • preop chemo for 8-12 wks followed by maintence chemo for 6-12 mo after surgial resection
    • common agents= adriamycin (doxorubicin), cis-platinum, methotrexate, and ifosfamide
    • 98% necrosis after neoadjuvant chemo is gd sign
  • trend towards LIMB SALVAGE whenever possible 3-4 wks after neoadjuvant chemo
  • equal survival limb slavage to amputation


What is periosteal osteosarcoma?


  • Intermediate grade osteosarcoma
  • extremely rare
  • occurs young adults 15-25 years
  • > females
  • occurs diaphysis of long bones
  • most common tibia and femur

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What is periosteal osteosarcoma genetically associated?


  • Ring chromosome 12
  • Germ line mutation of p53 found in 15-20% cases


What is the prognosis of periosteal osteosarcoma?


  • 25-30% pulmonary mets
  • Intermediate prognosis between parosteal and intramedullary osteosarcoma
  • 95 % necrosis post chemo is good prognostic sign


What are the symptoms and signs of periosteal osteosarcoma?


  • Symptom
    • Pain
    • 25% present with pathological fx
  • Signs
    • regional swelling and tenderness


Describe the radiographic features of periosteal osteosarcoma?


  • Sunburst/ hair on end appearance- periosteal reaction
  • usually no involvement of medullary canal
  • Bone scan usually HOT
  • Ct chest to exclude pulmnary mets

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what are the histological features of periosteal osteosarcoma?


  • tumour appears lobular and cartilaginous
  • chondroblastic matrix

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what is the tx of periosteal osteosarcomas?


  • Multiagent chemotherapy, limb salvage and adjuvant chemotherapy
  • Hillmann et al JBJS Am 1999. evaluated the functional outcomes of patients with distal femoral or proximal tibial tumors reconstructed with either endoprostheses or rotationplasties. They found that while no statistical difference exists between the two cohorts, patients with rotationplasties tended to have a greater level of activity, more normal gait, and were more confident in their limbs than the endoprostheses cohort. The cosmetic concerns regarding rotationplasties tended to be the largest problem with this method of surgical reconstruction.


what is telangectasia osteosarcoma?


  • Similar to classic osteosarcoma in epidemiology and genetics
    • male> female
    • rare
  • Similar location to ABC
    • prox humerus/prox femur/distal femur/prox tibia

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How do you differenitate telangiectatic osteosarcoma from aneurysmal bone cyst?


  • Fluid levels less defined on TOS
  • same bone locations
  • histology
    • lakes of blood mixed with malignant cells with mitotic bodies= TOS
    • blood filled spaces, spindle cells, benign gaint cells, no evidence of malignant cells= ABC

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what is the tx of telangectasis osteosarcoma?


  • multi-agent chemotherapy neoadjuvant & adjuvant and limb salvage

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