what is ews cancer?
<answer> Ewing's sarcoma is a malignant small, round, blue cell tumor, a rare disease in which cancer cells are found in the bone or in soft tissue. <context> Ewing sarcoma or Ewing's sarcoma (/ ˈ juː ɪ ŋ /) is a malignant small, round, blue cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue. The most common areas in which it occurs are the pelvis, the femur, the humerus, the ribs and clavicle (collar bone).