A tumor is a lump or mass of tissue that forms when cells divide uncontrollably. A growing tumor may replace healthy tissue with abnormal tissue. It may weaken the bone, causing it to break (fracture).
Most bone tumors are noncancerous (benign). Some are cancerous (malignant).Benign tumors are usually not life-threatening. Malignant tumors can spread cancer cells throughout the body (metastasize). This happens via the blood or lymphatic system.
Cancer that begins in bone (primary bone cancer) is different from cancer that begins somewhere else in the body and spreads to bone (secondary bone cancer).
The four most common types of primary bone cancer are:
Multiple myeloma is the most common primary bone cancer. It is a malignant tumor of bone marrow. Multiple myeloma affects approximately five to seven people per 100,000 each year. According to the Multiple Myeloma Research Foundation, more than 56,000 Americans are living with the disease each year. Most cases are seen in patients between the ages of 50 and 70 years old. Any bone can be involved.
Osteosarcoma is the second most common bone cancer. It occurs in two or three new people per million people each year. Most cases occur in teenagers. Most tumors occur around the knee. Other common locations include the hip and shoulder.
Ewings sarcoma most commonly occurs between 5 and 20 years of age. The most common locations are the upper and lower leg, pelvis, upper arm, and ribs.
Chondrosarcoma occurs most commonly in patients between 40 and 70 years of age. Most cases occur around the hip and pelvis or the shoulder.
There are many types of benign bone tumors. The more common types include:
- Non-ossifying fibromaunicameral (simple) bone cyst
- Giant cell tumor
- Fibrous dysplasia
For most bone tumors, the cause is unknown.
Most patients with a bone tumor will experience pain in the area of the tumor. The pain is generally described as dull and achy. The pain may or may not get worse with activity. The pain often awakens the patient at night.
Although tumors are not caused by trauma, occasionally injury can cause a tumor to start hurting. Injury can cause a bone that is already weakened by a tumor to break. This often leads to severe pain. Some tumors can cause fevers and night sweats. Many patients will not have any symptoms, but will instead note a painless mass.
Occasionally, benign tumors may be discovered incidentally when X-rays are taken for other reasons, such as a sprained ankle or rotator cuff problem.
If you think you might have a bone tumor, see your doctor as soon as possible for diagnosis and treatment.
Occasionally, infection, stress fractures, and other non-tumor conditions can closely resemble tumors.
Your doctor will collect detailed information about your general health and the tumor's type, size, location, and possible extent of spread.
Your doctor will need to take a complete medical history. This includes learning about any medications you take, details about any previous tumors or cancers that you or your family members may have had, and symptoms you are experiencing.
Your doctor will physically examine you. The focus is on the tumor mass, tenderness in bone, and any impact on joints and/or range of motion. In some cases, the doctor may want to examine other parts of your body to rule out cancers that can spread to bone.
Your doctor will probably obtain x-rays. Different types of tumors have different characteristics on x-ray. Some dissolve bone or make a hole in the bone. Some cause additional bone to form. Some can have a mixture of these findings.
Some tumors have characteristic findings on x-rays. In other cases, it may be hard to tell what kind of tumor is involved. More imaging studies may be needed to further evaluate some tumors. These may include magnetic resonance imaging (MRI) or computed tomography (CT).
Thighbone (femur) tumor. The x-ray shows a bone tumor in the middle of the thighbone. The tumor is also seen using magnetic resonance imaging (MRI). The insert at the top shows a coronal MRI. The insert at the bottom shows a cross-sectional MRI. The arrows on all images show the location of the tumor.
Upper arm (humerus) tumor and fracture. This x-ray shows a fracture through a tumor in the middle of the bone of the upper arm.
Blood tests and/or urine tests may be done. A biopsy is another test. A biopsy removes a sample of tissue from the tumor. The tissue sample is examined under a microscope.
There are two basic methods of doing a biopsy.
The doctor inserts a needle into the tumor to remove some tissue. This may be done in the doctor's office using local anesthesia. A radiologist may do a needle biopsy, using some type of imaging, such as an x-ray, CT, or MRI to help direct the needle to the tumor.
The doctor surgically removes tissue. This is generally done in an operating room. The patient is given general anesthesia, and a small incision is made and the tissue is removed.
In many cases, benign tumors just need to be watched. Some can be treated effectively with medication. Some benign tumors will disappear over time. This is particularly true for some benign tumors that occur in children.
If you are diagnosed with a malignant bone tumor, you might want to get a second opinion to confirm it. If you have bone cancer, the treatment team may include several specialists. These may include an orthopaedic oncologist, a medical oncologist, a radiation oncologist, a radiologist, and a pathologist. Treatment goals include curing the cancer and preserving the function of the body.
Doctors often combine several methods to treat malignant bone tumors. Treatment depends upon various factors, including the stage of the cancer (whether the cancer has spread):
- Localized Stage. Cancer cells are contained to the tumor and surrounding area.
- Metastatic Stage. Cancers have spread elsewhere in the body. Tumors at this stage are more serious and harder to cure.
Radiation therapy uses high-dose x-rays to kill cancer cells and shrink tumors.
Systemic Treatment (Chemotherapy)
This treatment is often used to kill tumor cells when they have spread into the blood stream but cannot yet be detected on tests and scans. Chemotherapy is generally used when cancerous tumors have a very high chance of spreading.
Generally, malignant tumors are removed using surgery. Often, radiation therapy and chemotherapy are used in combination with surgery.
Certain benign tumors can spread or become cancerous (metastasize). Sometimes the doctor may recommend removing the tumor (excision) or some other treatment techniques to reduce the risk of fracture and disability. Some tumors may come back, even repeatedly, after appropriate treatment.
Limb Salvage Surgery
This surgery removes the cancerous section of bone but keeps nearby muscles, tendons, nerves, and blood vessels. If possible, the surgeon will take out the tumor and a margin of healthy tissue around it. The excised bone is replaced with a metallic implant (prosthesis) or bone transplant.
Amputation removes all or part of an arm or leg when the tumor is large and/or nerves and blood vessels are involved.
When treatment for a bone tumor is finished, the doctor may take more x-rays and other imaging studies. These can confirm that the tumor is actually gone. Regular doctor visits and tests every few months may be needed. When the tumor disappears, it is important to monitor your body for signs that is may have returned (relapse).
Genetic research is leading to a better understanding of the types of bone tumors and their behaviors. Researchers are studying the design of metallic implants. This allows better function and durability after limb salvage surgery.
Advancements in the development of prosthetic limbs include computer technology. This is leading to better function and quality of life after amputation.
Research into new medications and new combinations of older medications will lead to continual improvements in survival from bone cancers. Your doctor may discuss clinical research trials with you. Clinical trials may involve the use of new therapies and may offer a better outcome.
The American Academy of Orthopaedic Surgeons
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