What is bone cancer? Bone is the framework that supports the
body. Most bones are hollow. Bone marrow is the soft tissue
inside hollow bones. The main substance of bone is made up of a
network of fibrous tissue onto which calcium salts are laid
down. This makes the bone very hard and strong. At each end of
the bone is a softer bone-like tissue called cartilage that acts
as a cushion between bones. The outside of the bone is covered
with a layer of fibrous tissue. The bone itself contains 2 kinds
of cells. Osteoblasts are cells that form the bone. Osteoclasts
are cells that dissolve bone. Although we think that bone does
not change, the truth is that it is very active. New bone is
always forming and old bone dissolving. The marrow of some bones
is only fatty tissue. In other bones the marrow is a mixture of
fat cells and the cells that make blood cells. These blood-
forming cells make red blood cells, white blood cells, and
platelets. Types of bone tumors Most of the time when someone is
told they have cancer i