Ewing's sarcoma is associated with

(A) CD-56 # Tumor cells in Ewing's sarcoma show diffuse membrane positivity for CD-56. Tumor cells are also positive for neuron-specific enolase.# Ewing's sarcoma (or Endothelial sarcoma of bone):> It is a highly malignant tumour, occurring between the age of 10-20 years.> Multicentric in origin.> Cytogenetic abnormalities associated with Ewing's sarcoma is the reciprocal translocation of the long arm of chromosomes 11 and 22> It arise in the diaphysis of long bone> Subperiosteal bone formation> Histopathologically -- Pseudo rosette formation.> The tumour grow fast and metastasises through the blood stream to the lungs and to other bones.# Clinical Features -- Pain, swelling and Fever, so it may be confused with osteomyelitis> X-Ray show - Onion peel appearance> Treatment - Highly radio sensitive tumour, so Radiotherapy is highly effective for control of the local tumour and chemotherapy for control of the metastasis.