Bone Sarcoma

The word 'sarcoma' is derived from the Greek word for 'fleshy'. Sarcomas arise from Mesenchymal tissue which is the precursor to fibrous tissue, muscle, bone and fat. Bone sarcoma is malignant tumor or cancer of the bone. The difference between the terms sarcoma and carcinoma is that while sarcomas spread through blood, carcinomas through lymph fluid to the nearby lymph nodes.

Symptoms of bone sarcoma

• Pain in the bones.
  
• Pain may worsen in the nights.
  
• Swelling, redness and tenderness at the site of bone pain.
  
• Swelling of the leg or arm in longer bones such as above or below the knee or upper arm, shoulder etc.
  
• Bone fracture after a routine movement – like throwing a ball.
  
• As cancer weakens bones, broken bones tend to occur more easily.
  
• Fatigue, fever and weight loss and anemia are other signs.
  

Causes of bone sarcoma

The cause is unknown in most cases although bone sarcoma can develop from benign lesions in the bone and areas that previously received radiation. Therefore persons who received radiation therapy or chemotherapy can be at increased risk. A genetic syndrome called Li Fraumeni and retinoblastoma and a disease called Paget's Disease are also associated with sarcoma.

Types of bone sarcoma

1. Osteosarcoma that occurs in the bones around the knee and upper arm.
2. Chondrosarcoma that begins at the cartilage and ends of bones and lines of joints and in pelvis, upper leg and shoulder.
3. The Ewing sarcoma family of tumors that occurs in bone but may also be present in the connective tissues located in the pelvis, legs and arms.
4. Multiple Myeloma which is a cancer of plasma cells that originates in bones.

Bone sarcoma diagnosis

A doctor examines the patient physically after ascertaining family medical history. Then the physician may recommend the following diagnostic tests:

• X rays in various parts of the body to show location, size and shape of bone tumor.
  
• Bone scans
  
• CT scans which reveal cross sectional images to check if the tumor has spread.
  
• MRI scans
  
• PET scans that image the body's metabolic action to show if cancer has spread.
  
• Biopsy
  

Treating Bone Sarcoma

Surgery plays a primary role in the treatment of bone sarcoma. The goal of surgery is twofold. On the one hand it can remove the cancerous tumors and restore the physical function and appearance. On the other hand, a cuff of normal tissue is taken from around the tumor cells to minimize the risk of tumor recurring at the local resection site.

After surgery, the reconstructive or plastic surgery team performs the delicate task of replacing bone. Musculoskeletal oncologists and reconstructive plastic surgeons use donor bone, the patient's own bone from other sites and metal implants to reconstruct limbs and restore function.

Radiation therapy: This can be performed before or after surgery or even during surgery though the use of brachytherapy. Radiation therapy is used to treat tumors or when there is disease recurrence at the site of the original tumor or other localized site. This is especially used in treating chondrosarcomas more often than bone sarcomas.

Chemotherapy: Chemotherapy is given before surgery in order to shrink the tumor and allow for better resection. Surgery and radiation can only act on a small area tumor site. Chemotherapy kills any cancer cells floating undetected elsewhere in the body.

Follow-up depends upon the grade and type of bone sarcoma. In case of Osteosarcoma and Chondrosarcoma, follow-up includes physical exam, chest x-ray which should be performed every three months for at least two years initially and then after four months for a year and then every six months for two years and subsequently annually.

Mesenchymal Chondrosarcoma

Mesenchymal Chondrosarcoma is an extremely rare malignancy of bone or soft tissue, often an aggressive form of bone cancer. It is a variant type of the conventional Chondrosarcoma which is a form of bone cancer arising from cartilage cells. Cartilage is a specialized tissue and it serves as a buffer or cushion at joints.

The skeleton of an embryo consists of cartilage which slowly converts into bone. In Mesenchymal Chondrosarcoma, approximately two-thirds affect the bones, especially the spine, ribs and jaws. In other cases, it affects the areas of the body other than bone, in soft tissues such as muscle and fat. Mesenchymal Chondrosarcoma occurs with greater frequency in young adults (aged 10-30). It is present in 2% of all chondrosarcomas and it has no sexual or racial predilection, but females are slightly more affected than males.

Signs and symptoms

Symptoms could vary depending upon the exact location and progression of tumor. Mesenchymal Chondrosarcoma mostly arise in the bones of the jaw, spine or the ribs. Tumors can develop in arms and legs frequently as well and especially in the femur (thigh bone). Tumors appearing as soft tissue masses can affect the muscle or central nervous system.

Some symptoms of Mesenchymal Chondrosarcoma resemble that of many other illnesses and disorders and this can lead to a false diagnosis initially. This is seldom the sickness that doctors perceive when presented with symptoms that match this rare cancer. It can generally be diagnosed without much difficulty when pain and swelling in the specific part of the body is located though other possibilities are usually tested first.

Although specific symptoms associated with Mesenchymal Chondrosarcoma are vague and non specific; yet many develop pain and swelling in the affected area. Lumps and joint stiffness are other clinical symptoms of the tumor. Such symptoms can be present even long before a diagnosis is made. One third of patients are symptomatic for more than one year. A large tumor can compress nearby structures and cause additional symptoms, for instance, a spinal cord paralysis, or if in the eye socket, can cause pain, swelling, visual disturbances and protrusion of the eyeball. Since this is an aggressive form of cancer, it can spread to other areas of the body - lungs, liver, lymph nodes and other bones and can cause life threatening complications.

Causes

While the exact cause of Mesenchymal Chondrosarcoma is unknown and investigations are ongoing, there is no identifiable risk factor for the development of Mesenchymal Chondrosarcoma that has been discovered.

Whereas, due to abnormal changes in the structures and orientation of cells known as oncogenes or tumor suppressor genes, these malignancies can develop. Current research shows that abnormalities of DNA, carrier of the body's genetic code can cause cellular malignant transformation. These abnormal genetic changes appear to occur quite spontaneously for unknown reasons.

Diagnosis

A diagnosis of Mesenchymal Chondrosarcoma may be difficult, but some seek attention due to pain and swelling. Diagnosis may be based upon clinical examination, and detailed patient history. A variety of specialized tests include X rays studies, a procedure in which a small sample of tissue is removed and studied under a microscope. A biopsy of a tumor or mass determines what type of cancer is present by identifying the cell type that makes up the tumor. In those suspected of Mesenchymal Chondrosarcoma, an open biopsy or a needle guided biopsy is recommended.

There are specialized imaging techniques that are used to evaluate the size, placement and extension of a tumor and to serve as an aid for future surgical procedures among those with Mesenchymal Chondrosarcoma. Such imaging techniques include CT scanning and MRI. Often CT scan of the lungs is performed as there is a risk of Mesenchymal Chondrosarcoma spreading to the lungs. Bone scans, tests that can detect areas of increased or decreased bone activity may be performed to determine whether Mesenchymal Chondrosarcoma has spread to affect other bones.

Clinical presentation

Like many other tumors, Mesenchymal Chondrosarcoma may metastasize thorough the blood and attack other organs within the body. It spreads to the lungs, though it may spread to other locations as well. When it appears near the spine, it is particularly troublesome. Depending upon the size of the tumor, it may place significant pressure on the spine and cause pain and partial paralysis. Should tumor be present in the skull, it can cause similar neurological problems.

Treating Mesenchymal Chondrosarcoma

To optimize treatment, a multidisciplinary group of health professionals at the time of suspicion of a bone sarcoma is highly recommended. Coordinated effort of a team of medical professionals is necessary to treat Mesenchymal Chondrosarcoma. While physicians specialize in the diagnosis and treatment of cancer, specialists in the use of radiation can treat cancer along with surgeons, oncology nurses and other specialists.

Specific therapeutic procedures and interventions vary depending upon numerous factors such as primary tumor location, stage of primary tumor and whether the tumor has spread to distant sites, individual's general health and other elements. Radiation may or may not be employed in the treatment of Mesenchymal Chondrosarcoma. Some medical oncologists advocate chemotherapy treatment plan. Radiation therapy post surgery is also typically standard practice for large tumors.

Since chances are that Mesenchymal Chondrosarcoma may recur after optimal therapy, patients should be routinely examined after surgery for follow up care. Surgical resection is the ideal method of treating Mesenchymal Chondrosarcoma assuming that the tumor can be removed without causing much damage to other organs or tissues.

Surgery is often followed up with chemotherapy and radiation to ensure that no cancerous cells are allowed to survive, grow and spread again. In case tumor is in an inoperable location, then radiation and chemotherapy can be used to shrink the tumor enough to allow for safe operation. Local sufficiently radical treatment for prevention of recurrence is vital. Patients have to avoid spicy food, smoking and drinking to avoid recurrence of the disease. Early detection and early diagnosis and treatment are the key to prevention and treatment of this disease.