What are Musculoskeletal Tumors?
Musculoskeletal tumors are masses or lumps of tissue that develop in or spread to the musculoskeletal system as a result of abnormal and uncontrollable cell division. The musculoskeletal system includes the bones, joints, ligaments, muscles, and nerves.
Musculoskeletal tumors are generally classified into two groups: muscle tumors and bone tumors. They are considered benign if they do not spread to other parts of the body, or malignant or cancerous if the cancer cells invade and kill nearby tissue and spread to other parts of the body.
Both benign and malignant tumors could arise from any bony tissue or mesenchymal soft tissue of the extremities, shoulder, girdle, pelvis, or the axial skeleton. Almost all tumors originate from one of the different histologic types of tissue that involve the musculoskeletal system: bone (osteoid-forming tumors), cartilage (chondroid-forming tumors), and muscle and the fibrous connective tissue (soft tissue tumors).
Types of Benign Musculoskeletal Tumors
Some of the types of benign musculoskeletal tumors include the following:
- Soft tissue tumors: These are more common than benign tumors of bone. They can occur at almost any site, including muscles, ligaments, nerves, and blood vessels. These tumors differ widely in appearance and behavior and some tumors can be quite aggressive. The majority of the tumors in this category are benign tumors of fat called lipomas. Other benign soft tissue tumors include angiolipoma, fibroma, neurofibroma, myxoma, and hemangioma.
- Chondroblastoma: This is a rare benign cartilaginous tumor that characteristically occurs in the epiphysis of a long bone in young patients. Despite being rare, they are one of the most frequently encountered benign epiphyseal tumors in skeletally immature patients.
- Giant cell tumor: This is a rare, aggressive non-cancerous tumor that generally occurs in adults between ages 20 and 40 when skeletal bone growth is complete. This usually develops near a joint at the end of the bone. The location of the tumor is often in the knee but can also involve the bones of the arms and the legs. It can also affect the flat bones, such as the breastbone or pelvis.
Risk Factors for Musculoskeletal Tumors
The causes of most musculoskeletal tumors are unknown, but some factors that increase the risk include:
- Previous radiation therapy
- Genetic factors and some inherited conditions, such as Li-Fraumeni syndrome
- Other bone conditions, such as Paget disease, fibrous dysplasia or multiple enchondromas
Symptoms of Musculoskeletal Tumors
Some of the common symptoms of musculoskeletal tumors include:
- Pain in the bones and joints
- Swelling over the affected area
- Stiffness or tenderness in the bone
- Difficulty with movement
- Loss of sensation in the affected area
- Fractured bone
What Happens if Benign Musculoskeletal Tumors are Left Untreated?
If a benign musculoskeletal tumor is allowed to progress without treatment, symptoms may get worse and new symptoms may develop over time.
Diagnosis of Musculoskeletal Tumors
In order to diagnose musculoskeletal tumors, your doctor may order the following diagnostic tests:
- Physical exam and review of medical history
- CT scan
- MRI scan
- Positron emission tomography (PET) scan
- Blood test
- Bone scan
- Bone biopsy, which analyzes a small sample of tissue to diagnose cancer
Treatment for Musculoskeletal Tumors
Benign musculoskeletal tumors are usually treated by surgery. This approach aims to remove the tumor and some of the healthy bone tissue that surrounds it.
Limb-sparing surgery, also known as limb salvage surgery, means that surgical intervention occurs without having to amputate the limb. The surgeon may take some bone from another part of the body to replace lost bone, or an artificial bone may be fitted. In some cases, however, amputation of a limb may be necessary.
Expandable endoprosthesis: Removal of bone tumors in children usually results in removal of one or more of the bone's growth plates. This can lead to a significant shortening of the limb when compared with the unaffected limb that continues to grow normally. Expandable prostheses can be used to non-invasively lengthen the limb. This is achieved by lengthening the prosthesis in small increments over time. The lengthening process is performed during follow up clinic visits and is done without further surgery or anesthesia.