Ewing sarcoma

2. EWING SARCOMA
• third most common nonhematologic primary
malignancy of bone,
• second most common (after osteosarcoma) in
patients younger than 30 years of age and the
• most common in patients younger than 10 years
of age.
• The incidence is less than 1 per 1 million per year,
accounting for about 9% of primary malignancies
of bone.
• Most occur in patients 5 to 25 years old.

3. • arise from mesenchymal stem cells in the bone
marrow
• Closely related to other tumours such as primitive
neuroectodermal tumour of soft tissues,
peripheral neuroepithelioma and Askin tumour.
• This highly malignant tumour occurs more
frequently in males, typically between 10 and 20
years of age,
• diaphyseal long-bone location but is equally as
common in flat bones.
• The femur is the most common long-bone site,
followed by the tibia, humerus and fibula, but
overall the pelvis accounts for the majority of
cases.

4. Presentation
• Pain , Usually the onset is insidious, may be of long
duration before the patient seeks medical attention.
• The pain may be only mild and intermittent initially
and may respond to initial conservative treatment.
• The average delay reported to be 34 weeks.
• may have fever, erythema, and swelling, suggesting
osteomyelitis.
• Laboratory studies may reveal an increased WBC , ESR ,
and an CRP level.
• needle aspirate may grossly resemble pus,

5. • Radiographically, an aggressive, permeative,
poorly defined osteolytic lesion with cortical
destruction, periosteal reaction and large, radiolucent
soft-tissue mass may be found.
• Periosteal reaction is common in young patients with
the lamellar ‘onionskin’ appearance causing fusiform
bone enlargement (Figure 9.29).
• This may mimic infection or eosinophilic granuloma in
young patients; subtle bone involvement with a large
soft-tissue mass could mimic primary bone lymphoma
in older patients

6. • Regardless of the location, MRI of the entire bone
should be ordered to evaluate the full extent of
the lesion, which typically extends beyond the
abnormality apparent on plain films.
• MRI is also useful to evaluate the extent of the
soft-tissue mass,
• radiograph and CT of the chest - site of
metastases.
• A bone scan - site of metastases.
• bone marrow aspirate - diffuse systemic disease.

7. • Histologically, Ewing sarcoma consists of small
blue cells with very little intercellular matrix.
• Cytogenetic or immunohistochemical studies
often are required to differentiate Ewing
sarcoma from other small blue cell tumors.
• Ewing sarcomas usually are periodic acid–
Schiff positive (owing to intracellular glycogen)
and reticulin negative.

8. worst prognostic factor
• presence of distant metastases.
• Even with aggressive treatment, patients with metastases have only
a 20% chance of long-term survival.
• Histologic grade is of no prognostic significance because all Ewing
sarcomas are considered high grade.
• Fever, anemia, and elevation of laboratory values (white blood cell
count, erythrocyte sedimentation rate, lactate dehydrogenase) have
been reported to indicate more extensive disease and a worse
prognosis.
• Older age at presentation (with a cutoff around 12 to 15 years old)
and male gender also have been reported to be associated with a
worse prognosis.
• As with osteosarcoma, histologic response to neoadjuvant
chemotherapy has been shown to be prognostically important.
• Greater than 90% necrosis after preoperative chemotherapy
indicates a good prognosis.

9. Treatment
• neoadjuvant or adjuvant chemotherapy, or both,
• Before the use of multiple-agent chemotherapy, long-term
survival was less than 10%.
• Today, most centers report long-term survival rates of 60%
to 75%.
• Local treatment of the primary lesion is more controversial.
• Ewing sarcoma is radiosensitive,
• Increased rate of overall survival with wide resection of the
primary
tumor. T
• large, central, unresectable tumors often are treated with
radiation, whereas smaller, more accessible lesions (which
inherently have a better prognosis) are more likely to be
treated with surgery.

10. • Repeat staging studies should be obtained
after neoadjuvant chemotherapy.
• The repeat radiographs often show increased
ossification, and repeat MRI often shows a
marked decrease in the soft-tissue mass.
• expected function after amputation, limb
salvage surgery, or radiation and the inherent
short-term and long-term risks involved with
each option.

11. • Disease relapse is associated with a poor
prognosis despite aggressive treatment of the
relapse with further surgery, radiation, and
chemotherapy.
• Patients with local recurrence have been
reported to have about a 20% 5-year survival
rate,
• Patients who relapse within the first year after
primary treatment have a worse prognosis than
patients who have an extended disease-free
interval.