Bone cancer is an uncommon cancer that begins in a bone. Bone cancer can begin in any bone in the body, but it most commonly affects the long bones of the arms and legs.
Several types of bone cancer exist. Some types of bone cancer occur primarily in children, while others affect mostly adults.
The term "bone cancer" doesn't include cancers that begin elsewhere in the body and spread (metastasize) to the bone. Instead, those cancers are named for where they began, such as breast cancer that has metastasized to the bone.
Bone cancer also doesn't include blood cell cancers, such as multiple myeloma and leukemia, that begin in the bone marrow — the jelly-like material inside the bone where blood cells are made.