Fibrosarcoma

A fibrosarcoma is a very rare tumor that begins in fibrous, connective tissue that wraps around your tendons, ligaments and muscles.

Types & Stages

There are two types of fibrosarcoma: 

• Infantile fibrosarcoma. Also called congenital fibrosarcoma, this is a type of tumor among the most common soft tissue sarcoma found in children under a year old. It presents as a rapidly growing mass at birth or shortly after. This form of fibrosarcoma is usually slow-growing and tends to be more benign than fibrosarcoma in older children, which behaves more like the type found in adults.
   
• Adult form fibrosarcoma. This type is most common in adults between ages 20 and 60. But it can also affect older children and adolescents between the ages of 10 and 15. It is more aggressive than the infantile form and generally involves more complex treatment.

Signs & Symptoms

Fibrosarcoma symptoms may include:

• painless or tender mass in an extremity or trunk
• pain or soreness caused by suppressed nerves and muscles
• limping or other difficulty using legs, feet, arms and hands
• tingling or “pins and needles” feeling or sharp, aching or burning pain 
• unusual swelling 

Diagnosis

Tests and procedures to diagnose a fibrosarcoma may include:

• Imaging tests. These may include: 
   
  • Magnetic resonance imaging (MRI). This is the most common imaging test for diagnosing fibrosarcomas. It can show a tumor’s size and location, and if it impacts blood vessels or nerves.
     
  • Computerized tomography scan (CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. 
     
• Biopsy. A provider may remove tissue from the lump (core needle biopsy), or they may cut it out entirely (excisional biopsy). A pathologist will check the tissue for cancer cells in a lab. 
   
• Immunohistochemistry (IHC). This lab test uses proteins called antibodies to determine whether a tumor is a fibrosarcoma or a different type of soft tissue tumor.

Treatment

For adult-type fibrosarcoma, healthcare providers typically use:

• Surgery. During surgery, surgeons remove the tumor and a margin of healthy tissue to ensure no cancer cells remain.
   
• Radiation therapy. You may need radiation therapy before surgery to shrink the tumor or afterward to destroy any remaining cancer cells.

For infantile fibrosarcoma, surgery to remove the tumor is often curative. Your child’s doctor may also recommend:

• Radiation and/or chemotherapy. These treatments can shrink tumors before surgery or destroy any remaining cancer cells after surgery. Unlike the adult type, most infantile-type fibrosarcomas respond well to chemotherapy.
   
• Targeted therapy. This treatment can stop cells from dividing too fast because of problems with the NTRK genes. It can shrink tumors, making surgery easier. 

Causes & Risk Factors

Risk factors can include: 

• Inherited conditions. These might increase your risk of developing fibrosarcoma: Familial adenomatous polyposis, Li-Fraumeni syndrome, Neurofibromatosis type 1, Nevoid basal cell carcinoma syndrome, Retinoblastoma, Tuberous sclerosis and Werner syndrome.
   
• Other conditions. Associated with fibrosarcoma include bone infarction (lack of blood flow causes bone cells to die); chronic (long-term) osteomyelitis; fibrous dysplasia and Paget’s disease of the bone.
   
• Previous radiation therapy. Directed toward the area with the tumor.
   
• Previous severe burn. At the tumor site.
   
• Exposure to certain chemicals. Including thorium dioxide, vinyl chloride or arsenic.
   
• Exposure to certain metals. In orthopedic implants, like chromium, cobalt or nickel.

Screening

There is no standard screening protocol for fibrosarcoma.