What are Soft Tissue Sarcomas?

Soft tissue sarcomas are rare tumors that arise from connective and supportive tissue of the body. This includes fat, muscle, nerves, bone, cartilage, vessels or fibrous structures.  These can occur in any part of the body.

Sarcomas Are a Rare and Heterogeneous Group of Malignant Tumors of Mesenchymal Origin and Are Approximately 1% of all Adult Malignancies and 12% of Pediatric Cancers.


Types of Soft Tissue Sarcomas

As classified by the World Health Organization (WHO), the group of soft tissue sarcomas includes more than 100 different histologic subtypes.

The main types of soft tissue sarcoma arise from:

  • Fat cells
  • Muscle
  • Peripheral nerves
  • Cartilage and other connective tissue
  • Blood and lymph vessels
  • Fibrous tissue


There are more than 80 subtypes of soft tissue sarcomas.

The most common subtypes are:

  • Undifferentiated pleomorphic sarcoma, previously called malignant fibrous histiocytoma
  • Liposarcoma
  • Leiomyosarcoma

Soft Tissue Sarcoma Symptoms

Soft tissue sarcomas tend to grow along tissue planes rarely traverse or violate major fascial planes or bone. They tend to spread via the bloodstream and can spread to the lungs.

  • Can occur anywhere
  • Gradually enlarging, painless mass
  • Pain or symptoms associated with compression by the mass, including
  • Paresthesias or edema in an extremity
  • Rarely constitutional symptoms, such as fever and/or weight loss

What Does Soft Tissue Sarcoma Look Like?

Sarcomas don’t have a typical appearance and are usually masses that are felt.

Unlike melanoma, soft tissue tumors rarely spread to lymph nodes except in a few specific histologic subtypes.

  • Rhabdomyosarcoma
  • Synovial sarcoma
  • Epithelioid sarcoma
  • Clear cell sarcoma
  • Vascular sarcomas (including angiosarcomas)
Risk Factors

Soft Tissue Sarcoma Risk Factors

  • Genetic predisposition
  • Li Fraumeni syndrome
  • NF type I
  • FAP and Gardner Syndrome
  • Retinoblastoma
  • Exposure to radiation therapy or chemotherapy
  • Chemical carcinogens
  • Chronic irritation
  • Lymphedema

Diagnosis can be difficult and is made based on morphologic pattern, immunohistochemical staining (IHC) and molecular diagnostics looking at specific chromosomal translocations.


Diagnosis and Evaluation

Tissue diagnosis is one the most important steps in patients with soft tissue sarcomas. Specific treatments differ based on the histologic subtypes. All patients should be presented in a multidisciplinary tumor board to get input from radiation oncologist, medical oncologist, genetic specialist, pathologist, radiologist and surgical oncologist.

Initial evaluation should include questions about history of when the mass was first noticed, how quickly it has been growing and if there are symptoms to suggest the mass is growing or pushing on vitals structures. A thorough physical exam should be performed.

Doctors looking at chart while walking through hallway

Soft Tissue Sarcoma Treatment

The treatment for soft tissue sarcoma depends heavily on the specific subtype of sarcoma, location, size and grade. Multi-modality care is used frequently to provide patients with the best outcome. All patients with sarcoma should be discussed in a multi-disciplinary tumor board to determine treatment plan.

  • Surgery – Removal of all cancer with intent of getting negative margins. Surgery remains the standard treatment of primary tumors. Important factors to consider are obtaining negative margins, re-operating if possible to get negative margins and not disrupting the tumor.
  • Radiation – in certain cases, can be given before or after surgery. Radiation is typically used in larger, higher grade tumors.
  • Targeted therapy – newer agents are being developed to target specific genes or proteins.
  • Chemotherapy – can be used alone or in combination with surgery and radiation.  Some subtypes have better responses to chemotherapy and should be evaluated at a center that routinely treats sarcoma.
  • Immunotherapy – ongoing clinical trials are evaluating the role of immunotherapy in soft tissue sarcomas.

When to see a Provider

Submit an online appointment request or call  310-829-8781 if you observe changes in the appearance of your skin, such as finding a new growth, a change to a previous growth, or a recurring sore.