Myxofibrosarcoma (MFS) is a soft tissue sarcoma cancer that develops in connective tissue, and it might develop in the deeper connective tissues that surround the muscles. The connective tissues play a crucial role in supporting and protect the organs by providing a structural framework. This includes tissues such as bones, cartilage, and fat. It typically develops in the arms and legs and may appear like a lump.

MFS is initiated by the proliferation of cells that have the potential to develop into healthy bodily tissue. This growth can cause a slow increase in the size of a lump under the skin. Generally, MFS does not cause any pain, and it is more commonly seen in individuals who are over 50 years of age.

MFS is an aggressive form of cancer that quickly metastasizes to other parts of the body. Its treatment typically involves surgery to remove the cancer, along with chemotherapy and radiation therapy as additional options. However, MFS has a higher risk of recurrence following treatment compared to some other types of cancer.


Initially, myxofibrosarcoma may not manifest any noticeable symptoms. However, as the tumor progresses, you may have:

  • Lump under the skin
  • Pain or discomfort
  • Swelling


Myxofibrosarcoma’s cause is unknown, but it, like other forms of cancer, occurs due to a mutation in the DNA of cells, prompting them to replicate. This replication leads to the formation of an abnormal mass known as a tumor.

Risk factors

Several factors, including MFS, can raise the risk of developing malignant soft tissue tumors.

  • Age: This is commonly seen in individuals over the age of 50.
  • Gender: Males are more affected than females.
  • Genetics: Certain hereditary disorders may increase the risk of soft tissue sarcoma.
  • Environmental factors: Exposure to herbicides and arsenic are two pollutants that could potentially increase the risk.
  • Radiation therapy: Previous radiation therapy may also increase the risk of developing myxofibrosarcoma.