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introduction_ewing sarcoma.pptx

Ewing Sarcoma 
Bone tumor
Nuha Al-Sharif
Marwa Taweel
Dina 
INTRO

  • Identified in 1921 by James Ewing
  • either neuro-ectodermal or stem cell origin
  • Primary Bone Cancer
  • Ewing’s Sarcoma Family of tumors:
    • Ewing’s sarcoma (Bone –87%)
    • Extraosseous Ewing’s sarcoma (8%)
    • Peripheral PNET(5%)
    • Askin’s tumor
Epidemiology
  • 9% of primary bone sarcomas
  • 4th most common primary malignancy of bone but 2nd most common bone cancer in children
  • Age Group – 95% patients age between 5 to 30 yrs ,most range between 5 to 15 yrs
  • Sex - Male – 60%
  • M:F 1.3:1 < 10 yrs 1.6:1 > 10 yrs
  • More common in Whites (95%)
  • No known predisposing factor
Ewing Vs PNET
Similarity between Ewings and PNET
  • radiology, light microscopy
  • Chromosomal translocation t(11:22)(q24:q12)
  • Reactivity towards p30/32 MIC-2 in 90%

Differences : In PNET
  • More frequent epiphyseal involvement, Pathological fractures, metastasis
  • Rosette formation
  • Electron microscopy – features of neural differentiation like dendritic processes, abundance of cytoplasmic granules, intermediate filaments, neurosecretory granules and microtubule formation.
  • Immunohistochemistry - +ve for neural markers – S-100, synaptophysin, NSE, neuro-filament protein.
  • Pain & swelling of affected area
  • May also have systemic symptoms:
    • Fever
    • Anemia
    • Weight loss
    • Elevated WBC & ESR,LDH
  • Pathological fracture
Clinical Presentation
Location
  • Can develop in any bone
  • Usually of diaphyseal origin. Sometimes dia-metaphyseal rarely, metaphyseal.
  • In vertebrae, most commonly involved – Sacrum
10%
22 %
11%
F - 9%
8
12
6
1
3%
Histo-pathology
Gross Description :
  • Diaphyseal/dia-metaphyseal
  • Predominantly medullary, then extends to haversian system and cortex
  • Greyish-white to pink in color
  • soft, friable
  • Often of semi-liquid consistency
  • Areas of hemorrhage, necrosis and cyst formation present
  • Onion-skin periosteal reaction
  • One of many ‘small round blue cell’ tumors seen in pediatrics
  • Poorly differentiated tumor
  • Unknown origin, Thought to be of neural crest progenitor cells origin
Microscopy
  • Small round undifferentiated tumor cells with little cytoplasm and indistinct borders
  • Round nuclei with stippled evenly distributed powder-like chromatin and 1-2 nucleoli
  • Frequent mitosis
  • Necrosis and Ghost cells
  • Minimal inter-cellular substance
  • Rosette and psuedo-rosette formation
  • Perithelioma
  • NO GIANT CELLS
  • PAS +ve  presence of glycogen
  • Reactive for vimentin
Rosette and psuedo-rosette formation
Differentials & Groups
Small-round-cell tumor differential (by age)
< 5 yrs: neuroblastoma or leukemia
5-10 yrs: eosinophilic granuloma
5-30 yrs: Ewing's sarcoma
>30 yrs: lymphoma
> 50 yrs: myeloma
  • t(11;22)(q24;q12) leads to the formation of a fusion protein (EWS-FLI1) present in 85 % of the cases

  • can be identified with PCR and useful to differentiate Ewing sarcoma from other round cell lesions
  • Also seen:
    • t(21;22)(q22;q12) 5-10%EWS/ERG
    • t(7;22) and t(17;22) the remainderEWS/ETV1 and EWS/E1AF respectively
    • t(1;16)(q21;q13)present along with t(11;22)
  • The c-myc protooncogene is frequently expressed in Ewing’s.
Cytogenetics
  • direct extension into adjacent bone or soft tissue.

  • Hematogenous Spread
  • 25% present with
  • metastatic disease

Nearly all pts. have micromets at diagnosis, so all Need chemo.
Routes of spread
Prognostic Factors
Survival


  • 60-70% survival with isolated extremity disease
  • 40% long term survival with pelvis lesions
  • 15% long term survival if patient presents with metastatic disease
Other Differential diagnosis
chronic osteomyelitis
Metastatic Neuroblastoma
Histiocytosis
osteosarcoma 
  • Imaging Ct scan X-Ray MRI Bone scan
(PET) scan
  • Lab tests
  • Biopsy •excisional •inscisional
  • IHC : CD99 , MIC2
  • Diagnostic Work-Up
X-Ray
Fig: bone scan shows increased activity in the distal femur.
Bone Scan: Ewing Sarcoma of Left Humerus demonstrates Intense Uptake
Gross Pathology: Ewing Sarcoma of Metadiaphysis of Proximal Humerus. (Top arrow) Permeative Marrow Lesion.
(Bottom arrow) Surrounding Soft Tissue Mass
Bone Scan
PET/PET- CT Scan
Radiology
  • Onion skin formation
Hair-on-end periosteal reaction
Metatarsal involvement with moth-eaten appearance, periostitis
Involvement of long bone with lamellated appearance, saucerisation, cortical breach, periostitis
  • Ewings sarcoma with extensive soft tissue involvement
Treatment
  • All patients require chemotherapy
    • Induction chemotherapy
    • Maintenance chemotherapy
Chemotherapy
  • Advantage of this approach:
    • Evaluation of effectiveness .
    • Decreases the vol. of local therapy .
    • bone healing .
Chemotherapy (cont.)
  • Surgical Indications
    • Expendable bone
    • Bone defect able to be reconstructed with modest loss of function
    • May consider amputation if considerable growth remaining
    • After pre-op RT
  • Limb-salvage surgery is preffered.
Surgery
Radiotherapy detail
  • Patient may be treated in supine ,prone, or lateral position site dependent.
  • 6MV of energy used
  • For limb, opposing fields normally used.
  • Field should not cross joints unless essential.
  • Indications for RT: After induction chemotherapy
Overview of Ewing’s tumor treatment
Relapse
  • 30-40% of patients develop relapse with <20% survival
  • Early relapse – less than 2 years
  • Late relapse – more than 2 years
  • Second most common childhood bone tumor.
  • Small round cell tumor with CD99 (MIC2), PAS positive
  • Lytic lesion with onion peel appearance on X-Ray
  • Overall survival with localized disease (55%) and metastatic disease 22%
  • Multimodal treatment approach
Conclusion
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