Cancer

Cancer is a group of diseases characterized by uncontrolled growth of tissue cells in the body and the invasion by these cells into nearby tissue and migration to distant sites. Cells are the building blocks of living things.
Cancer grows out of normal cells in the body. Normal cells multiply when the body needs them, and die when the body doesn't need them. Cancer appears to occur when the growth of cells in the body is out of control and cells divide too quickly. It can also occur when cells forget how to die.
There are many different kinds of cancers. Cancer can develop in almost any organ or tissue, such as the lung, colon, breast, skin, bones, or nerve tissue.

Ewing tumors

Ewing's sarcoma is a primary bone cancer that affects mainly children and adolescents. It's one of a group of cancers known collectively as the Ewing sarcoma family of tumors -- ESFT or sometimes just EFT. It's the second most common bone cancer in children, but it's also relatively uncommon. It accounts for only 1% of all childhood cancers. Although it can occur at any age, it very rarely occurs in adults over the age of 30.
Because many illnesses can cause the same symptoms as Ewing's sarcoma, it's sometimes missed in its early stages. But early diagnosis and treatment is important.