Musculoskeletal Tumors

"The origin of osteosarcoma is in some cells that can be altered by the growth of the child. It is a tumor linked to growth".


What is a musculoskeletal tumor?

A musculoskeletal tumor is a growth of cancer cells in bone or muscle tissue.

A bone tumor is an abnormal proliferation of cells of a certain strain within a bone. They are divided into 2 groups: malignant or benign, according to their ability to spread (metastasize) to other organs and tissues.

Within the benign lesions, there is also a particular group called paratumoral lesions, which are not strictly speaking tumors, but which resemble them. An example of these lesions are bone cysts.

Depending on the cell line from which the tumor originates, both malignant and benign tumors are classified as bone formers, cartilage formers, giant cell tumors, etc. Each of these has a different prognosis and treatment.

At the Clínica Universidad de Navarra, in the last 20 years we have treated a thousand malignant primary bone tumors. In osteosarcoma, the most frequent, survival is 74% at 10 years. The upper limb is preserved in 90% of cases. In the treatment of Ewing's sarcoma, our center's survival rate is 65%.

The Clínica Universidad de Navarra also has experience in the treatment of soft-tissue sarcomas associated with surgical resection by means of brachytherapy.


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What are the symptoms of musculoskeletal tumors?

The most common symptom of bone and other musculoskeletal tumors is pain in one limb.

It is usually constant, even at night, so that it wakes the patient up. The most frequent location is the knee of a growing child, although it can also appear in the bones of the trunk, pelvis, etc.

Sometimes it is accompanied by a lump that grows quickly. It is not usually accompanied by affectation of the general state, nor fever or other symptoms.

The duration of these symptoms is very variable, but usually last a few weeks or months because, unlike benign tumors, grow quickly.

Having pain at night is not synonymous with having a sarcoma, but almost all sarcomas debut in this way.

The most common symptoms are:

  • Pain in the extremity.
  • Nocturnal pain.
  • Inflammation and swelling of the limb.

Do you have any of these symptoms?

You may have a musculoskeletal tumor

What are the causes?

The cause that produces most malignant tumors of the skeleton is unknown.

However, we know that cancer is a genetic disease, not because it is transferred from parents to children (although it sometimes occurs), but because at its origin is some alteration of the genes that control the multiplication of cells.

Currently, much progress is being made in the study of these alterations and it is hoped that in the near future action will be taken on the genes that cause them. In the samples obtained from each patient, innumerable genetic studies are carried out for this purpose.

In some sarcomas (the name given to malignant tumors of the musculoskeletal system), the specific genetic alteration that has produced them is known. The new laboratory techniques in this field that have been produced in recent years have also led to great advances in the diagnosis and prognosis of these lesions and, in the future, will allow for more specific treatment for each tumor.

With these genetic studies, some sarcomas can be diagnosed with certainty in less than 24 hours and, furthermore, it can be known whether that sarcoma has a greater or lesser chance of responding to treatment.

What is your prognosis?

The type of tumor, location, size, presence or not of metastasis at the time of diagnosis, the response of the tumor to chemotherapy, etc. are factors of great importance in order to establish a prognosis.

It is essential that the diagnostic process and the start of treatment are as fast as possible. Delays can compromise patient survival.

When suspecting a malignant bone tumor, the most sensible thing to do is to go to an experienced center, where survival and the possibilities of preserving the limb are greater than in other centers.

In the Clínica Universidad de Navarra, the survival rate of osteosarcoma is 74% at 10 years, with a rate of preservation of the limb greater than 90%.

In the case of osteoid osteoma, percutaneous treatment under CT control has made it possible to cure after the failure of open surgery. The same occurs with conservative surgery of soft tissue tumors, which in many cases achieves cure.

How are musculoskeletal tumors diagnosed?


Given the low incidence of these tumors, it is very important that the team of specialists involved in the diagnosis be experts in this pathology.

Diagnostic tests:

  • As far as imaging methods are concerned, the most specific is simple radiography.
  • Magnetic resonance imaging has proved very useful in sarcomas to assess the local extent of the lesion.
  • Other imaging tests that are used for the diagnosis and follow-up of these patients are the scanner, the gammagraphy and the PET.
  • The scanner or computerized axial tomography (CT) is primarily used to rule out or confirm the presence of pulmonary metastases. In most sarcomas, no metastases are detected at the time of diagnosis. But if this occurs, the chances of cure are lower. 
  • With the bone scan (which consists of the injection by vein of a substance that is deposited in the areas of the skeleton where there is some alteration), we can detect whether there are bone metastases or multifocal (polyostotic) lesions.
  • Positron emission tomography (PET) is also very sensitive to detect lesions at a distance from the main tumor, to assess its metabolism, etc.
  • The biopsy can have important prognostic and therapeutic consequences and should therefore always be performed by the team that will definitively treat the patient. It is preferable to carry out the biopsy with a needle or trocar, in a closed (unopened) space to avoid the spread of the tumour.

How are different types of bone and soft tissue tumors treated?

The numerous medical advances in the diagnosis and treatment of bone tumors allow the limb to be maintained.

A bone tumor is an abnormal proliferation of cells within a bone. In most malignant tumors of the skeleton, the cause is unknown.

Much progress is being made in the study of gene alterations in order to be able to act on them in the near future. Countless genetic studies are being carried out for this purpose on samples obtained from each patient.

The most frequent symptom is constant pain in a limb. The most common location is the knee of a growing child, although it can also appear in the bones of the trunk, pelvis, etc. Sometimes, it is accompanied by a lump that grows quickly.

The diagnosis must be based on the clinical history, images and biopsy. It is essential that the diagnosis and the beginning of treatment be as fast as possible so as not to compromise the survival of the patient.

The treatment of these tumors must also be based on three pillars: surgery, chemotherapy and, sometimes, radiotherapy, for almost a year, although with intermittent hospital admissions. Currently, the possibilities of keeping the limb unamputated are very high.

Within the benign lesions, there is a particular group called paratumoral lesions. These are not strictly speaking tumors, but rather an abnormal proliferation of cells. An example of these lesions are bone cysts.

The osteoid osteoma is a benign bone tumor characteristic of children and adolescents. It is very small in size (like a pea) and causes continuous pain, predominantly nocturnal, which is improved with anti-inflammatory drugs (e.g., aspirin®).

Surgical removal of the tumor has been the classic treatment. However, percutaneous treatment under CT control is on the rise: percutaneous resection or radiofrequency thermocoagulation.

It has the advantages of reducing surgical risk and facilitating correct localization of the lesion. In addition, recovery is much faster (it can be performed on an outpatient basis), does not require immobilization or use of crutches afterwards, etc.

Soft tissue tumors are rare and there are few expert centers.

The delay in diagnosis, the appearance of a recurrence or metastasis can worsen the prognosis, which a specialized center can cure.

They appear in muscle, ligaments, fat, blood vessels, etc., usually in a limb. The most frequent are liposarcoma, malignant fibromo histiocytoma and synovial sarcoma.

The main symptom is a lump in the soft parts of a limb. They are usually painless. As it increases in size it may hurt, especially when pressing on the muscles and nerve endings.

It is diagnosed by means of magnetic resonance. If a lesion is confirmed, a biopsy is performed. And if the tumor is aggressive, a thoracic CT scan is performed to rule out pulmonary metastases.

The treatment is surgical. The Clinic is one of the few accredited centers in Europe to perform hyperthermia with TNF, which has demonstrated a high rate of local control of the disease.

The treatment of some types of sarcoma has also benefited from new drugs, such as STI-571 (Glevec®).

In addition, the introduction of brachytherapy into the treatment protocol makes it possible to reduce the dose of external radiation, thereby reducing the side effects arising from it.

Important lines of research are being developed in molecular biology focused on diagnosis.

Where do we treat them?


The Sarcomas Area of the
Cancer Center Clínica Universidad de Navarra

The Sarcomas Area is one of the most prestigious centers in the world in this field. Its team of professionals is internationally recognized in this field of medicine.

In our center, all diagnostic tests (including biopsy) can be performed, usually in less than 24 hours. We also have teams of highly trained professionals in intra-arterial chemotherapy, brachytherapy, isolated limb perfusion, etc.

Imagen de la fachada de consultas de la sede en Pamplona de la Clínica Universidad de Navarra

Why at the Clinica?

  • Integral evaluation of the patient.
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