A bone cancer (sarcoma) is a bone tumor that contains cancer (malignant) cells. A benign bone tumor is an abnormal growth of noncancerous cells.

A primary bone tumor originates in or near a bone. Most primary bone tumors are benign, and the cells that compose them do not spread (metastasize) to nearby tissue or to other parts of the body.

Malignant primary bone tumors account for fewer than one percent of all cancers diagnosed in the United States. They can infiltrate nearby tissues, enter the bloodstream, and metastasize to bones, tissues, and organs far from the original malignancy. Malignant primary bone tumors are characterized as either bone cancers that originate in the hard material of the bone or soft-tissue sarcomas that begin in blood vessels, nerves, or tissues containing muscles, fat, or fiber.

Osteogenic sarcoma, or osteosarcoma, is the most common form of bone cancer. It...