The second largest group of sarcomas is bone sarcomas, or bone cancer. There are three types of bone sarcoma: osteosarcoma; Ewing's sarcoma; and chondrosarcoma. Bone sarcomas are very rare with approximately 2,890 new cases diagnosed each year in the United States and approximately 1,410 deaths. The incidence is slightly higher in males than females, and no race has a higher incidence than another, although Ewing's sarcoma is more common among Americans of European descent. Bone sarcomas are most likely to be diagnosed in children; and because of the rarity and severity of bone cancer, a bone cancer specialist, such as a pediatric oncologist or orthopedic oncologist, should be consulted in treating the disease. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Bones are made up of three types of tissue: compact tissue (the hard outer part of the bone), spongy tissue (spongy tissue inside the bone containing the bone marrow), and subchondral tissue (the bone smooth joints). Cartilage surrounds the subchondral tissue to form a cushion around the joints. Bone tumors can be benign (noncancerous) or malignant (cancerous). Benign bone tumors are rarely life-threatening and do not spread within the body; however, they can grow and compress healthy bone tissue. Cancer that develops in the bone is called primary bone cancer. It differs from secondary bone cancer that spreads to the bone from another part of the body. Primary bone cancer is rare with approximately 2,500 new cases diagnosed each year in the United States (this figure includes bone cancer that is not a sarcoma). The most common type of primary bone cancer is osteosarcoma. Because it occurs in growing bones, it is most often found in children. Another type of primary bone cancer is chondrosarcoma which is found in the cartilage. This cancer occurs most often in adults. Ewing sarcoma can present as a bone sarcoma or a soft tissue sarcoma depending on its original location in the tumor. Scientists are not sure what causes bone cancer, however they have been able to identify some factors that could put a person at risk. Children and young adults who have undergone radiation therapy or chemotherapy for other diseases are at increased risk of bone cancer. Additionally, adults with Paget's disease, a disease characterized by the abnormal growth of new bone cells, have an increased risk of osteosarcoma. There are also some hereditary conditions that can increase the risk of bone cancer. Symptoms of bone cancer can vary depending on the size and location of the tumor. Pain is the most common symptom. Tumors that arise in or around joints often cause swelling and tenderness. Tumors can also weaken bones, causing fractures. Some other symptoms may be weight loss, fatigue and/or anemia. The first step in diagnosing primary bone cancer is a complete medical history and physical examination performed by a doctor. Your doctor may order a blood test to determine the level of an enzyme called alkaline phosphatase. About 55% of patients with primary bone cancer will have elevated alkaline phosphatase levels. However, it is not a completely reliable indicator for bone cancer since bone growth in children will cause an increase in the enzyme. X-rays are also used to locate a tumor. If an x-ray suggests the presence of a tumor, your doctor may order additional tests such as a CT scan, magnetic resonance imaging (MRI), or angiogram. Finally, it is necessary.