Bone Tumors

Tumors are abnormal masses or lumps. They’re formed when cells divide out of control, and spread excessively throughout the body. Bone tumors can be found in any bone in the body, and in any part of the bone—from the surface down to the bone marrow (the spongy tissue inside the bone).



Most bone tumors are benign (non-cancerous), but some may be malignant (cancerous).


While benign tumors are usually not life-threatening, they can still cause problems for the body. Benign tumors that are still growing can destroy healthy tissue and make it easier for bones to fracture (break).

There are also several benign conditions that can resemble tumors—like a non-ossifying fibroma, which is a bundle of fibrous tissue that usually appears in the leg.  Your child’s doctor can diagnose the problem and recommend the correct treatment.

The common types of benign bone tumors, and some conditions grouped with tumors, include:

  • Non-ossifying fibroma and fibrous dysplasia: These are growths that are made of fibrous tissue in the body.
  • Giant cell tumor: This is a tumor formed when small cells merge into larger ones.
  • Aneurysmal bone cyst: This tumor forms where there is damage to the part of the bone where growth occurs.
  • Unicameral (simple) bone cyst: This cyst is a cavity (hole) in a bone that’s filled with fluid.
  • Enchondroma: This type of tumor begins in the cartilage—tissue that protects bones and joints.  
  • Osteoid osteoma: This is a small tumor that does not grow, but causes a bone to grow around it. It also creates an osteoid bone, which is abnormal bone material.  
  • Osteochondroma: This is an abnormal growth that develops near a growth plate—an area of growing tissue at the end of the long bones (e.g., thighbone, shinbone) in a child or adolescent.  
  • Chondroblastoma: This tumor grows at the ends of a child’s long bones, close to the joints.



Malignant bone tumors can consist of two types of cancer: primary or secondary. Primary cancers begin in the bone, while secondary cancers begin somewhere else in the body and spread to the bone.

Primary bone cancers are rare—they account for about 3 to 7 percent of all childhood cancers. The two most commonly found in children are:

  • Osteosarcoma: This is the most common bone cancer in teenagers. It usually develops in areas where bones grow rapidly, like at the end of long bones in the arms or legs. It’s most often found in the bones around the knee.
  • Ewing sarcoma: This is slightly less common, and it mostly affects young teenagers. It generally begins in the ribs, shoulder blades, pelvic (hip) bones, or the long bones in the arms or upper legs.


Both of these primary bone cancers can spread to other bones, as well as soft tissue and lungs.

Secondary bone cancers (also called metastatic cancers) can come from anywhere in the body, like nerve or muscle tissue.



It’s possible that a child will have a lump, but won’t notice any other symptoms.

If she does have symptoms, she may complain of dull, achy pain in the area around the tumor. The pain may get worse at night or with physical activity. The tumor could also cause fever or night sweats.


Most bone tumors do not have a known cause. However, a child may start to show symptoms after an injury. The injury could cause a tumor to start hurting, or cause a bone that’s already been weakened by a tumor to break.


Getting an accurate diagnosis for a bone tumor is very important, since other conditions can resemble tumors.

A child’s physician will examine the tumor. He may request X-rays to help identify and diagnose the tumor. He may also conduct a biopsy—a procedure that removes a bit of the tumor—to determine whether it’s benign or malignant.  ​


The type of treatment depends on whether the tumor is benign or malignant. There are surgical and non-surgical options for both.

These treatments may include:

  • Traditional cancer treatments like radiation or chemotherapy
  • Medication
  • Surgery to remove the tumor
  • A combination of any of the above treatments


Since the causes of bone tumors are unclear, researchers don’t yet know of a certain way to prevent them.

The OIC Bone Tumor Team

The Musculoskeletal Bone and Soft Tissue Tumor Program at OIC was the first of its kind in the Western United States when it opened its doors in 1962. It remains one of a few centers in the nation dedicated specifically to bone tumors.

From its inception the program has utilized a multidisciplinary approach to provide comprehensive care for children with benign and malignant tumors involving bone and soft tissue.

The Musculoskeletal Bone and Soft Tissue Tumor Program at OIC prides itself on having assembled the most balanced, multi-disciplinary tumor team in Los Angeles, and one of the most comprehensive teams in the country. The team strives to accommodate the patient's needs and emotional concerns, while providing optimum tumor care.

The tumor team includes surgeons, chemotherapists, pathologists, radiation therapists, electron microscopists, radiologists, social workers and nurse specialists.

As with all rare diseases, a dedicated center improves outcomes and lowers complication rates. Orthopaedic Institute for Children has documented these improvements. In addition to the clinical program, OIC is devoted to ongoing basic science research in bone tumors, microvascular surgery, and prosthetic design.