Sarcoma cancer cell. Coloured transmission electron micrograph (TEM). Sarcomas are cancers of the connective tissues, which include muscles, blood vessels, nerves and fat. Sarcomas are a rare type of cancer and are often hard to detect. These cells are from a Ewing sarcoma, a malignant round-cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue. It mainly affects children and young people, but is also seen in adults. It's more common in males than females.Magnification: x2000 when printed 10 centimetres wide