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Flashcards in tumour like lesions Deck (67):

What is fibrous dysplasia?

  • A developmental abnormality caused by failure of the production of normal lamellar bone
    • areas of the skeleton remain poorly mineralised tabeculae
  • females > males
  • found any ages
  • 75% pts <30 yrs 
  • location
    • any bone can be involved
    • Prx femur, rib, maxilla and tibia


What are the genetics of fibrous dysplasia?

  • GS alpha protein ( chromosome 20q13) activating mutation
  • Affects cAMP signalling pathway -> increased production of cAMP
  • not inherited
  • high production of FGF-23 may-> hypophosphataemia


Name the associated conditions of fibrous dysplasia?

  • McCune Albright Syndrome
    • cafe au lait spots in coast of maine- sharp/irreg
    • Preococious puberty
    • renal phosphate wasting due to FGF-23( oncogenic osteomalacia)
    • unilateral polyostotic fibrous dysplasia
  • ​Mazabraud syndrome
    • ​polyostotic fibrous dysplasia
    • soft tissue intramuscular myxomas
  • Osteofibrous dysplasia
    • rare form that primarily affects the tibia & is confined to cortices

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What is the prognosis of  fibrous dysplasia?

  • 1% risk of malignant transformation to 
  • osteosarcoma
  • fibrosarcoma
  • malignant fibrous histocytoma
  • Poor prognosis


What is the presentation/symptoms of  fibrous dysplasia?

  • Swelling or deformity
  • lesions maybe
    • monostotic 80%
    • polyostotic 20%
  • Pain from stress fx

On examination

  • cafe au lait spots- maybe present
    • larger/irreg border cf NF spots


What are the radiographs of  fibrous dysplasia?

  • Central lytic lesion in medullary canal( diaphyseal/metaphyeal)
    • may have cortical thinning w expansile lesion
  • Highly lytic lesion/ ground glass appearance
  • "punched out lesion" sclerotic margin
  • Shepherd's crock deformity
  • vertebral collapse & kyphoscoliosis
  • Bone scan- usually warm

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What does histology of  fibrous dysplasia show?

  • typical "Alphabet soup/ chinese letters"
  • fibroblast proliferation surrounded by woven bone
    • woven bone lacks osteoblastic rimming

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What is the tx of  fibrous dysplasia?

Non operative

  • Observation
    • asymptomatic pts
  • Bisphosphonate therapy
    • for symptomatic polyostotic fibrous dysplasia
    • effective in reducing pain/ bone turnover


  • Internal fixation and Bone grafting
    • symptomatic lesions/ impending/actual fx/ severe deformity
    • never use autogenous BG as bone will turn into FB use cortical/canc allograft
    • IM nails more effective than plating in Lower limb
  • Osteotomies
    • for deformity


What is osteofibrous dysplasia? 

  • A rare form of fibrous dysplasia that primary affects Tibia
  • confined to cortices
  • usually younger children
  • males> females
  • location
    • ​ant tibia
  • Genetics
    • Doesn't have Gs alpha activating mutation cf  fibrous dysplasia
    • trisomy 7,8,12,22 reported

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What is the prognosis of osteofibrous dysplasia?

  • lesions usually regress & don't cause problems in adulthood


What are the symptoms and signs of osteofibrous dysplasia?

  • Asymptomatic
  • painless swelling
  • anterior/ anterolateral bowing of tibia
  • pseudoarthrosis develops in 10-30%


  • local tenderness over tibia


What radiographic features is seen in  osteofibrous dysplasia?

  • Anterior eccentric lytic lesions in a child -> tibial bowing
  • usually diaphyseal
  • no periosteal reaction
  • confined to anterior cortex
  • ddx includes adamantioma

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What is the histology in osteofibrous dysplasia?

  • Similar to fibrous dysplasia except Osteoblastic rimming is present- see pic

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What is the tx of osteofibrous dysplasia

Non operative

  • Observation
    • first line of tx- for most pts this alone
  • Bracing
    • deformity significant and interfering w walking


  • Deformity correction w osteotomy
    • rarely needed
    • significant deformity
    • preform after skeletal maturity


What is Paget's disease?

  • A condition of abnormal bone Remodelling
    • original osseous tissue is reconstructed thru active interplay between excessive bone resorption and abnormal new bone formation
  • Increase osteoclastic bone resorption is primarily cellular abnormality
  • cause = slow virus infection
    • paramyxovirus
    • respiratory syncytial virus
  • Peak incidence 5th decade
  • common causcians
  • males= females
  • location
    • monostotic/polyostotic
    • femur, pelvis, tibia, skull, spine


What are the genetics of Paget's disease?

  • Most spontaneous
  • familial clusters 40% autosomal dominant transmission
  • mutations - 4 found
    • most important SQSTM1 - worse Paget's


What are the orthopaedic manifestations of Paget's disease?

  • Bone pain
  • Long bone bowing
  • fx - due to brittle bones- tend to be transverse
  • Large joint OA


What is the prognosis of Paget's disease?

  • Paget's sarcoma
    • <1% will develop Paget's sarcoma( 2ary sarcoma)
    • Osteosarcoma is most common then fibrosarcoma & chondrosarcoma
    • most common in pelvis, femur and humerus
    • poor prognosis
      • 5 yr survival for non mets Paget's sarcoma is <5%
      • tx with Chemo & wide surgical resection


What is the classification of Paget's disease?

  • 3 phases
  1. Lytic- intense Osteoclast reabsorption
  2. Mixed- resorption/compensatory bone formation
  3. Sclerotic- osteoblastic bone formation

All 3 phases may coexist in same bone



What is the presentation of Paget's disease?

  • Asymptomatic
    • found incidentally
  • Pain
    • stress fx
    • increase vascularity and warmth
  • New onset of Pain and swelling
    • 2ary sarcoma
  • Cardiac Symptoms
    • can pc- High output cardiac failure particularly if large/multiple lesions and pre-exisiting dimished cardiac function


What is seen in radiographs with Paget's disease?

  • Coarsened trabeculae give bone a blastic appearance
  • lytic phase
    • blade of grass/flame shaped lucent advanced edge
  • mixed- lytic and sclerotic w coarsened trabeculae
  • sclerotic- bone enlargement w cortical thickening- see pic
  • long bone bowing
  • fx
  • osteitis circumscripta- cotton wool exudates in skull

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What is seen in bone scan of Paget's disease?

  • Accurately marks site of disease
  • intensely HOT in LYTIC and MIXED phase
  • Less HOT in sclerotic phase


What is seen in lab results of Paget's disease?

  • Elevated serum alk phosphatase
  • elevated urinary hydroxyproline ( collagen breakdown)
  • Increase urinary N telpeptide, alpha- C telopeptide and deoxypyridinoline
  • Normal calcium levels


What is seen in histology of Paget's disease?

  • Woven bone and irregular braod trabeculae with disorganised cement lines in a mosaic pattern
  • numerous large osteoclasts w multiple nuclei per cell

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What is the tx of Paget's disease?

Non operative

  • Observation and supportive tx
    • asymptomatic pts
    • physio, nsaids, oral analgesics
  • Bisphosphonates
    • alendronate, risedronate oral - 

      inhibits oc and ob

    • pamidronate- iv, inhibits only oc
  • Calcitonin
    • = Oc to shrink in size and decrease bone resorptive activity within minutes


    • need to tx to reduce bleeding esp THR - not in lytic phase
    • > incidence of suboptimal aligment 2ary to pagetoid bone highest in TKR
  • Metaphyseal osteotomy and plate fixation
    • fx thru path bowing of long bones
    • impending fx


What is Histocytosis X or Langerhans cell histiocytosis?

  • A spectrum of diseases of the reticuloendothelial system with one in three general presentations
  1. Eosinophilic granuloma (EG)- is a tumor like condition secondary to proliferation of histiocytes, usually a self limited lesion found in younger pts​
  2. Hand-Schuller-Christian Disease (HSC)- chronic, disseminated form of bone & visceral lesions, aKA langerhans cell histocytosis w visceral involvment
  3. Letterer-Siwe disease- a fatal form that occurs in young children

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What is the epidemiology of histocytosis X?

  • Most common in children 80% <20 yrs
  • Hand-Schuller-Christian disease= children > 3 yrs
  • Letter-Siwe disease- <3 years
  • Male : female 2:1
  • location
    • Eosinophilic granuloma
      • skull/ribs/clavicle/scapula/mandible
      • isolated lesions of thoracic spine most common
    • HSC
      • Multiple bony sites
      • multiple skull lytic lesions
  • No clear genetics


What is the prognosis of histocytosis X?

  • Eosinophilic granuloma
    • isloated involvment generally treatable
    • spine lesions spontaneously resolve
  • HSC
    • prognosis depends on response to chemo
    • worsening prognosis w increasing extraskeletal involvment
  • LSD
    • generally fatal in children <3 yrs

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What is the symptoms of eosinophilic granuloma?

  • Pain and swelling in region of involvement
  • localised/diffuse back pain
  • HSC
    • multiple skull lytic lesions- similar to MM
    • diabetes insipidus
    • exopthalmos
    • visceral involvment- diffuse/ non specific adbo/chest pain

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What is seen on xrays of eosinophilic granuloma?

  • Known as the great mimicker similar to 
  • osteomyelitis, lymphoma, fibrous dysplasia, Ewing's sarcoma
  • Diaphyseal lesions
    • well defined lytic/punched out- see pic
    • cortex thinned/expanded/destroyed
    • may have periosteal reaction
  • Metaphyseal lesions
    • extend up to but not thru physis
    • less central location cf diaphyseal lesions
  • Spine
    • vertebra plana- flattened vertebra
    • increased kyphosis

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What is seen on histology of eosinophilic granuloma?

  • Langerhans cells
    • mononuclear histocyte like cells w oval nuclei w well defined round/ oval cytoplasm
    • a prominent nuclear groove ( coffee bean nuclei) can be seen in most of the nuclei- blue arrow

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Describe the tx of eosinophilic granuloma?

Non operative

  • Observational
    • a self limited process so can be tx by obs alone
  • Bracing
    • prevent kyphosis of spine
      • will correct deformity in 80% pts
      • vertebral lesions general regain 50% height
  • Low dose Radiation 600-800 cGy
    • for lesions in spine that compromise stability
    • effective most lesions
  • Chemotherapy
    • Diffuse HSC
    • methotrexate/vinblastine
    • prognosis improved w less severe extraskeletal involvement
  • Corticosteriod injection
    • isolated lesions, post currettage


  • Curettage and bone grafting
    • Lesions that endanger articular surface or at risk of fx
  • Spinal deformity correction
    • progressive spinal deformity refractory to bracing
    • 10% will need op.

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What is Myositis Ossificans?

  • A form of Heterotrophic Ossification that is the result of
    • Direct trauma
    • Intramuscular haematoma
  • Most common location is Diaphysis of bone
  • Must differentiate from tumours
  • Fibrodysplasia ossificans progressiva (FOP) is a rare subtype of HO - Stone man's disease
    • mutation of ACVR1 gene ( activin A type 1 receptor gene)
    • progressive HO (muscles/fascia/tendons/lig/joint capsule) w great toe abnormality ( hallux varus/malformed MT

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What are the symptoms of myositis ossificans?

  • Pain that decreases with time
  • Size of mass that decreases with time
  • O/E
    • palpable mass
    • restricted rom- see pic

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What is seen on xrays of myositis ossificans?

  • Perpherial bone formation with central lucent area
  • May appear as dotted vein pattern

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What is the tx of myositis ossificans?

Non operative

  • rest, range of motion exercises, and activity modification
    • passive strecthing is CI- makes worse!


  • Surgical excision
    • Only if it remains a problem after it matures
    • Don't operate in acute phase, wait at least 6/12- cold on bone scan


What is Melorheostosis?

  • Rare, Benign Painful devleopmental dysplasia of cortical bone. effecting the extremities charcterised by formation of Periosteal new bone formation
    • usually before 40 yrs
    • M=F
    • lower extremities > upper
    • Non hereditary

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What are the symptoms of Melorheostosis?

  • Pain
  • reduced ROM
  • Joint contractures


  • fibrosis of the skin w induration/ erytherma
  • reduced rom
  • painful hyperostoses

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What is seen on radiographs of Melorheostosis?

  • Cortical Hyperostosis
    • Dripping candle wax w dense hyperostosis that flows along the cortex of the bone
    • Hyperostosis may flow across the joints

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What is seen on histology of Melorheostosis?

  • Normal Haversian systems with enlarged bone trabeculae & without cellular atypia or mitotic figures

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What is the tx of Melorheostosis?

Non operative

  • Symptomatic TX
    • mild symptoms with adequate motion


  • Hyperostotic bone resection w contracture release
    • severe contractures/ limited mobility & apin


What is heterophic ossification?


  • Atypical formation of bone in extraskeletal tissues
  • usually occurs spontaneously or following trauma
  • within 2/12 of neurological ( brain) injury)
  • most often found between muscle and joint capsule

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Where are the common locations of heterophic ossification?

  • post brain injury
    • hip> elbow > shoulder>knee
    • Elbow Ho > post brain trauma
    • occurs on affected spastic side
    • rarely in the knee
  • post spinal cord injury
    • hip> knee>elbow>shoulder
    • Hip flexors and Abductors >Extensors and adductors
    • Medial aspect of knee

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What is the pathophysiology of HO?


  • Unknown but genetic predisposition
  • Experimental HO assoc with tissue expression of cAMP


What are the associated conditions of HO?


  • Pathological fx
    • reduced rom & osteoportic bone
  • Nerve impingement
  • Soft tissue contractures
  • Complex regional pain syndrome
  • Joint ankylosis
  • HO post THR affects outcome


What are the risk factors for developing HO?


  • Injury severity score- 11%
  • Traumatic brain injury- 11%
  • Spinal injury-20%
  • Neurological compromise
  • Decubitus ulcers
  • Antegrade femoral nail site-25%
  • Distal femoral traction pins
  • Amputation thru zone of injury
  • THR - 53% but only 5% significant
  • TKR
  • Surgical Approach-extended iliofemoral> kocher- langerbeck> ilioinguinal


What is the presentation of HO?


  • Painless loss of ROM
  • Interfes with ADL
  • CRPS symptoms
  • Fever


  • Ankylosing of joints
  • loss of movement
  • neurological signs


What is HO seen on imaging?


  • xrays
    • ossification easy to visualise
    • bony cortex= maturity
    • trabecular pattern
    • sharp demarcation from surrouding tissues
  • USS
    • for early dx of HO
    • echogenic surfaces with posterior acoustic  shadowing
  • Bone scan
    • triphasic for early dx

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what is seen labs results with HO?


  • Elevated alkaline phosphatase
  • Elevated CRP
  • Elevated CK
    • extent of muscle involvement

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Describe the tx of HO?



  • Bisphosphonates & NSAIDS
    • Indomethacin 75mg/day for 6 weeks
  • Perioperative radiotherapy
    • 700-800cGy < 4hours pre op or within 72 hrs post op
      • no literature support
      • thought to be effective against Osteoblast differentiation
      • prevents proliferation/differentation of pirmordial mesenchymal cells

Post traumatic

  • Wide exposure and surgical ressection
    •  for severe loss of rom
    • timings contraversial - 6 mths General surgery, 1 year Spinal cord injury
    • fu with 5 days course of indomethacin


Describe the complications of HO?


  • Haematoma and post op bleeding
  • Infection
    • higher rate of infection post Thr if HO present
  • Fx of osteoporotic bone
    • osteopenia from diuse
    • during surgery/physio
  • Recurrence
    • > if neurological compromise
  • AVN


what is tumoral calcinosis?


  • Rare
  • Calcium salts deposited in extra-capsular soft tissues
  • more common in
    • Females
    • Afro-Caribbean
  • typcially occurs around joints
    • shoulders
    • hips
  • Unknown pathophysiology but thought to be due to abnormality of Phosphorus metabolism

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Describe the associated conditions of tumoral calcinosis?


  • Calcinosis of Renal Failure
  • similar to tumour calinosis but not so concentrated to hips/shoulders
  • assoc with hyperphosphataemia, chronic renal failure, long term dialysis


What are the presentations of tumoral calcinosis?

  • Mass and swelling typically around joints
  • Pain secondary due to compression


  • Palpable mass


What seen on imaging of tumoral calcinosis?


  • circular or oval well demarcated masses of calcium around joint
  • direct involvement of bones/joint rare


  • Demonstrate masses with fluid levels

Bone scan

  • increase uptake in calcific masses

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What is the tx of tumoral calcinosis?


Non operative

  • Observation
  • for non symptomatic pts


  • Complete surgical excision
    • for symptomatic lesions
    • complete surgical resection to reduce chance of reocurrance

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What is this ?

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  • Bone infarct


What is a bone infarct?


  • Thought to be same spectrum as osteonecrosis
  • occurs within Metaphysis or Diaphysis of long bones
  • risk factors
    • Trauma
    • Sickle cell
    • Connective tissue disorders
    • Gaucher's disease
    • Steriod use
  • Aetiology= Interuption of blodd supply by intrinsic/extrinsic factors

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What is the presentation of bone infarcts?

  • often Asymptomatic
  • Insidential finding


What is seen on imaging of bone infarcts?


  • Xrays
    • Medullary lesion of sheet like central lucency surrounded by sclerosis with a serpiginous border
    • "Smoke up the Chimney"
  • ​MRI
    • ​Central signal remains of normal marrow- see pic
    • T2
      •  acute infarct may show ill-defined non-specific area of high signal
      • intense inner ring of granulation tissue and a hypointense outer rong of sclerosis
  • Bone scan
    • Cold in early phases
    • hot in resorptive/revascualrisation phase

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What is the tx of bone infarcts?

  • Non operative
    • Observation
    • usually asymptomatic no tx required


What is focal fibrocartilaginous dysplasia?

  • A Benign Dysplasia -> Unilateral varus of tibia
  • Usually seen in infants/toddlers
  • Aetiology and pathogenesis unknown

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What is the presentation of focal fibrocartilaginous dysplasia?

  • Unilateral Tibial Vara
  • Knee Hyperextension with lateral thrust

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What is seen on xray of focal fibrocartilaginous dysplasia?

  • Abrupt varus at Metaphyseal- Diaphyseal junction
  • Cortical sclerosis at Medial cortex
  • Radiolucency may appear just proximal to area of cortical sclerosis corresponding to fibrocartilaginous tissue

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What is the histology of focal fibrocartilaginous dysplasia

  • A prominent layer of collagenic fibrous tissue with thick dense fibrocartilagenous tissue

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What is the tx of focal fibrocartilaginous dysplasia?

Non operative

  • Observation
  • majority spontaneously correct beacuse of the normal proximal tibial physeal growth


  • Deformity correction
  • maybe necessary if the deformity progresses or fails to resolve during a period of observation or orthotic management


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