What Is Bone Cancer?

Bone cancer is very rare in adults. It starts in the cells that make up the bone. Cancer starts when cells begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other parts of the body. To learn more about how cancers start and spread, see What Is Cancer?

Normal bone tissue

To understand bone cancer, it helps to understand a little about normal bone tissue.

Bone is the supporting framework of your body. Most bones are hollow. The hard outer layer of bones is made of compact (cortical) bone, which covers the lighter spongy (trabecular) bone inside. The outside of the bone is covered with fibrous tissue called periosteum. Hollow bones have a space called the medullary cavity which contains the soft, spongy tissue called bone marrow (discussed below). The tissue lining the medullary cavity is called endosteum.

At each end of the bone is a zone of a softer form of bone-like tissue called cartilage. Cartilage is softer than bone but more firm than most tissues. It's made of a fibrous tissue matrix mixed with a gel-like substance that doesn't contain much calcium. Most bones start out as cartilage. The body then lays calcium down onto the cartilage to form bone. After the bone is formed, cartilage may remain at the ends to act as a cushion between bones. This cartilage, along with ligaments and other tissues connect bones to form a joint. In adults, cartilage is mainly found at the end of some bones that are part of a joint.

Cartilage is also in the chest where the ribs meet the sternum (breastbone) and in parts of the face. The trachea (windpipe), larynx (voice box), and the outer part of the ear are other structures that contain cartilage.

Bone is very hard and strong. Some bone is able to support as much as 12,000 pounds of pressure per square inch. It takes as much as 1,200 to 1,800 pounds of pressure to break the femur (thigh bone).

Bone itself contains 2 kinds of cells.

  • The osteoblast is the cell that lays down new bone
  • The osteoclast is the cell that dissolves old bone.

Bone often looks as if it doesn’t change much, but it's actually very active. New bone is always forming while old bone is dissolving.

In some bones the marrow is only fatty tissue. In other bones it's a mixture of fat cells and blood-forming cells. The blood-forming cells make red blood cells, white blood cells, and blood platelets. There are other cells in the bone marrow, too, such as plasma cells and fibroblasts.

Any of these bone cells can develop into cancer.

Types of bone tumors

Bone tumors that are not cancer

Some tumors that start in the bone are benign (not cancer). Benign tumors do not spread to other tissues and organs and are not usually life threatening. They often can be cured with surgery. Types of benign bone tumors include:

  • Osteoid osteoma 
  • Osteoblastoma 
  • Osteochondroma
  • Enchondroma
  • Chondromyxoid fibroma.

 Benign tumors are not discussed further here.

Bone metastases

Most of the time when someone with cancer is told they have cancer in the bones, the doctor is talking about a cancer that has spread to the bones from somewhere else. This is called metastatic cancer. It can happen with many different types of advanced cancer, like breast cancer, prostate cancer, and lung cancer. When the cancer cells in the bone are looked at under a microscope, they look just like the tissue they came from.

So, if someone has lung cancer that has spread to bone, the cancer cells in the bone look and act like lung cancer cells. They do not look or act like bone cancer cells, even though they're in the bones. Because these cancer cells still act like lung cancer cells, they need to be treated with drugs that are used for lung cancer.

To learn more about this, see Bone Metastasis.

Blood cancers

Other kinds of cancers that are sometimes called “bone cancers” start in the blood-forming cells of the bone marrow − not in the bone itself.

The most common cancer that starts in the bone marrow and causes bone tumors is called multiple myeloma. Another cancer that starts in the bone marrow is leukemia. Sometimes lymphomas, which more often start in lymph nodes, can start in bone marrow. These blood cancers are not discussed here.

Bone cancers

True (or primary) bone tumors start in the bone itself and are called sarcomas. These are malignant tumors, which means they're cancer.

Sarcomas start in bone, muscle, fibrous tissue, blood vessels, fat tissue, as well as some other tissues. They can develop anywhere in the body. They're covered below.

Malignant bone tumors

There are many different kinds of primary bone cancer. They're named based on the part of the bone or nearby tissue that's affected and the kind of cells forming the tumor. Some are quite rare.


Osteosarcoma (also called osteogenic sarcoma) is the most common primary bone cancer. It starts in the bone cells. It most often occurs in young people between the ages of 10 and 30, but about 10% of osteosarcoma cases develop in people in their 60s and 70s. It's rare in middle-aged people, and is more common in males than females. These tumors develop most often in bones of the arms, legs, or pelvis. This type of bone cancer is covered in Osteosarcoma.


Chondrosarcoma starts in cartilage cells. It's the second most common primary bone cancer. It's rare in people younger than 20. After age 20, the risk of getting a chondrosarcoma goes up until about age 75. Women get this cancer as often as men.

Chondrosarcomas can start anywhere there's cartilage. Most develop in bones like the pelvis, legs, or arms . Sometimes chondrosarcoma starts in the trachea, larynx, or chest wall. Other sites are the scapula (shoulder blade), ribs, or skull.

Benign (not cancer) tumors are more common in the cartilage than malignant ones. These are called enchondromas. Another type of benign cartilage tumor is a bony projection capped by cartilage called an osteochondroma. These benign tumors rarely turn into cancer. People who have many of these tumors have a slightly higher chance of developing cancer, but this isn't common.

Chondrosarcomas are classified by grade, which measures how fast they grow. The grade is assigned by the pathologist (a doctor specially trained to examine and diagnose tissue samples with a microscope). The lower the grade, the slower the cancer grows. When a cancer is slow growing, the chance that it will spread is lower, so the outlook is better. Most chondrosarcomas are either low grade (grade I) or intermediate grade (grade II). High-grade (grade III) chondrosarcomas, which are the most likely to spread, are less common.

Some chondrosarcomas have distinctive features which can be seen with a microscope. These sub-types of chondrosarcoma often have a different prognosis (outlook):

  • Dedifferentiated chondrosarcomas start out as typical chondrosarcomas but then some parts of the tumor change into cells like those of a high-grade sarcoma (such as high grade forms of malignant fibrous histiocytoma, osteosarcoma, or fibrosarcoma). This type of chondrosarcoma tends to develop in older patients and grows faster than usual chondrosarcomas.
  • Clear cell chondrosarcomas are rare and grow slowly. They seldom spread to other parts of the body unless they have already come back several times in the original location.
  • Mesenchymal chondrosarcomas can grow rapidly, but are sensitive to treatment with radiation and chemotherapy.

Ewing tumor

Ewing tumor is the third most common primary bone cancer, and the second most common in children, teens, and young adults. It's rare in adults older than 30. This cancer (also called Ewing sarcoma) is named after Dr. James Ewing, who first described it in 1921. Most Ewing tumors develop in bones, but they can start in other tissues and organs. The most common sites for this cancer are the pelvis, the chest wall (such as the ribs or shoulder blades), and the long bones of the legs or arms. Ewing tumors occur most often in white people and are very rare among African Americans and Asian Americans. More information can be found in Ewing Family of Tumors.

Malignant fibrous histiocytoma

Malignant fibrous histiocytoma (MFH) most often starts in soft tissue (connective tissues such as ligaments, tendons, fat, and muscle); it's rare in bones. This cancer is also known as pleomorphic undifferentiated sarcoma, especially when it starts in soft tissues. When MFH occurs in bones, it usually affects the legs (often around the knees) or arms. This cancer most often occurs in elderly and middle-aged adults. It's quite rare in children. MFH mostly tends to grow locally, but it can spread to distant sites, like the lungs.


This is another type of cancer that develops more often in soft tissues than it does in bones. Fibrosarcoma usually occurs in elderly and middle-aged adults. Bones in the legs, arms, and jaw are most often affected.

Giant cell tumor of bone

This type of primary bone tumor has benign (not cancer) and malignant forms. The benign form is most common. Giant cell bone tumors typically affect the legs (usually near the knees) or arms of young and middle-aged adults. They don’t often spread to distant sites, but after surgery tend to come back where they started . (This is called local recurrence.) This can happen many times. With each recurrence, the tumor becomes more likely to spread to other parts of the body. Rarely, a malignant giant cell bone tumor spreads to other parts of the body without first recurring locally.


This primary tumor of bone usually occurs in the base of the skull and bones of the spine. It develops most often in adults older than 30. It's about twice as common in men as in women. Chordomas tend to grow slowly and often do not spread to other parts of the body. They often come back in the same area if they are not removed completely. The lymph nodes, the lungs, and the liver are the most common areas for tumor spread.

Other cancers that develop in bones

Other cancers can be found in the bones, but they don't start in the actual bone cells. They are not treated like primary bone cancer.

Non-Hodgkin lymphomas

Non-Hodgkin lymphoma generally develops in lymph nodes but sometimes starts in the bone. Primary non-Hodgkin lymphoma of the bone is often a widespread disease because many bones are usually involved. The outlook is similar to other non-Hodgkin lymphomas of the same subtype and stage. Primary lymphoma of the bone is given the same treatment as lymphomas that start in lymph nodes − it's not treated like a primary bone sarcoma. For more information see Non-Hodgkin Lymphoma.

Multiple myelomas

Multiple myeloma almost always develops in bones, but it's not a primary bone cancer because it starts in the plasma cells of the bone marrow (the soft inner part of some bones). Although it causes bone destruction, it's no more a bone cancer than leukemia is. It's treated as a widespread disease. At times, myeloma can be first found as a single tumor (called a plasmacytoma) in a single bone, but most of the time it will spread to the marrow of other bones. See Multiple Myeloma.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

National Cancer Institute. Bone Cancer. March 13, 2008. Accessed at www.cancer.gov/types/bone/bone-fact-sheet on December 4, 2017.

National Cancer Institute. Osteosarcoma and Malignant Fibrous Histiocytoma of Bone Treatment (PDQ®)–Patient Version. September 1, 2017. Accessed at www.cancer.gov/types/bone/patient/osteosarcoma-treatment-pdq on December 4, 2017.


National Cancer Institute. Bone Cancer. March 13, 2008. Accessed at www.cancer.gov/types/bone/bone-fact-sheet on December 4, 2017.

National Cancer Institute. Osteosarcoma and Malignant Fibrous Histiocytoma of Bone Treatment (PDQ®)–Patient Version. September 1, 2017. Accessed at www.cancer.gov/types/bone/patient/osteosarcoma-treatment-pdq on December 4, 2017.

Last Revised: February 5, 2018

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