Fibrosarcoma is a malignant mesenchymal tumor derived from fibrous connective tissue around the bones. The condition is rare but can spread and divide quickly.
What is fibrosarcoma?
A fibrosarcoma is a rare, malignant type of soft tissue sarcoma that is made of fibrous connective tissues that connect, support, and surround the bones. They can spread and divide incredibly quickly.
Initial symptoms are not obvious, however, over time, you may notice a lump or swelling that may increase in size, pain or tenderness in the same area, fatigue, and unintentional weight loss.
A confirmed diagnosis of fibrosarcoma is difficult due to their rarity. The prognosis is generally poor due to the condition's aversion to radio and chemotherapy and a high rate of recurrence. Surgical resection is a common method of treatment.
You should see your primary care doctor in the next few days to have your symptoms evaluated. It is likely that your physician will want to perform imaging (x-ray or MRI).
In its early stages, a fibrosarcoma usually does not cause any obvious signs or symptoms. However, over time, the following symptoms may arise:
- A lump or swelling: This may or may not increase in size.
- Pain and/or tenderness: This occurs specially if a tumor presses on surrounding nerves or muscles.
- Unintentional weight loss
In general, any cancer is the result of cells dividing and growing uncontrollably. Fibrosarcoma originate in the cells of fibrous tissues called fibroblasts then spread aggressively into other bones such as the femur, tibia and mandible. Fibrosarcoma have a characteristic pathologic finding of spindled fibroblasts or myofibroblasts which are immature, not fully functioning forms of normal, adult fibroblasts. These immature fibroblasts divide rapidly and spread quickly. The exact cause of the uncontrollable growth related to fibrosarcoma is not completely known or understood; however, genetics, age, gender, and certain exposures can increase the risk of development.
Genetics, age, and gender
There are two types of fibrosarcoma: a congenital form that occurs in infants under the age of 1 and an adult form. The following factors affect the risk of development in different ways.
- Genetics: People with certain inherited conditions such as Neurofibromatosis Type 1 or Tuberous Sclerosis can often develop fibrosarcoma.
- Age: Fibrosarcoma most commonly occur in people between the ages of 25 to 79, but the peak for the adult-type is between 30 and 60 years of age.
- Gender: Depending on the source, men and women can develop the disease at equal rates.
People with the following exposures are more at risk than the general population:
- Chemical exposure: Certain chemicals such as herbicides and arsenic may increase the risk of fibrosarcoma and other types of soft tissue sarcomas.
- Radiation exposure: Prior radiation treatment for other cancers can also increase risk for development of fibrosarcoma.
- Inherited syndromes: As mentioned above, fibrosarcoma are associated with inherited genetic syndromes.
Treatment options and prevention for fibrosarcoma
Treatment for fibrosarcoma is based upon the following factors:
- Grade, size and location of the primary mass
- Age and health
- Extent of spread (if the cancer has spread)
- Recurrence of previous fibrosarcoma or other cancer
The diagnosis of fibrosarcoma is a difficult one. There are many, similar spindle-cell shaped sarcomas, so there is a high chance of misdiagnosis and inappropriate treatment. Proper identification and diagnosis is key for adequately preventing and/or minimizing spread of the disease.
Your physician will conduct a biopsy of the mass in order to fully examine the cells and makeup of the tumor. This biopsy can either take small samples from different parts of the tumor (core needle biopsy) or take a larger sample via surgery.
Surgery, radiation, and chemotherapy
The three main treatment modalities for cancer include surgery, radiation therapy, and chemotherapy. Fibrosarcoma have a low sensitivity to toward radiation therapy and chemotherapy, so surgical removal is first-line standard therapy. Follow-up radiation or chemotherapy after surgery also usually has a low response rate, and use will largely depend on how much of the area was affected during surgery.
Unfortunately, the overall prognosis for fibrosarcoma is quite poor due to the aggressive nature of the cancer and its poor response to chemotherapy. Furthermore, fibrosarcoma have a high rate of recurrence despite treatment.
There are many novel methods in the works for slowing proliferation and migration of tumor cells as well as increasing sensitivity to chemotherapy. Hopefully with these efforts to identify new drugs and treatment options, the outlook for people with fibrosarcoma will improve.
When to seek further consultation for fibrosarcoma
Make an appointment as soon as possible if you notice the following symptoms:
- A lump/bump of any size located deep within the muscle tissues
- A lump/bump that is increasing in size
- A lump/bump that becomes painful over time
- Recurrence of a lump/bump that has been removed
Questions your doctor may ask to determine fibrosarcoma
- How would you explain the cause of your knee pain?
- How long has your knee pain been going on?
- How severe is your knee pain?
- Is your knee pain getting better or worse?
- Is your knee pain constant or come-and-go?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
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- Risk Factors for Soft Tissue Sarcomas. American Cancer Society. ACS Link. Updated April 6, 2018.
- Treatment of Soft Tissue Sarcomas, by Stage. American Cancer Society. ACS Link. Updated April 6, 2018.
- Grimer RJ. Size Matters for Sarcomas! Annals of The Royal College of Surgeons of England. 2006;88(6):519-524. doi:10.1308/003588406X130651. NCBI Link.
- What is Sarcoma? Sarcoma Foundation of America. SFA Link.