Soft tissue sarcoma (STS) is a type of cancerous tumor that can grow in the body’s soft tissues. If it occurs in the thigh, it may feel like a person has a lump in their thigh, though symptoms may not be present at first.

STS occurs in soft tissues such as the blood vessels, muscles, nerves, and fat.

A person with soft tissue sarcoma in the thigh. -1Share on Pinterest
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STS can occur in the thigh.

Although STS can occur in any part of the body, most STS tumors start in the limbs, and 44%Trusted Source of them occur on the thigh.

In addition to the legs, STS can occurTrusted Source in the:

  • arms
  • belly
  • internal organs
  • trunk
  • neck
  • head

Some types of STS occur more often in particular body areas.

The types of sarcomas that most oftenTrusted Source develop in the thigh are as follows:

  • Fibromyxoid sarcoma or Evan’s tumor: These types of STS are usually painless and slow-growing and typically occur in the legs, arms, or trunk.
  • Liposarcomas: These are cancerous growths of fat tissue that usually develop in the thigh, in the belly, or behind the knee. Fewer than 20%Trusted Source of all cases of STS in the United States are liposarcomas.
  • Solitary fibrous tumors: These tumors usually do not spread to other tissues or structures and may be either benign or malignant. They usually occur in the thigh, pelvis, underarm, or in the lining around the lung (the pleura).

People may not experience any symptoms during the early stages of STS. Because STS can occur deep within flexible tissue, tumors may grow for some time, moving and stretching healthy tissue out of the way before a person notices any symptoms.

A common symptom of STS in a limb, such as the thigh, is an area of swelling or a lump. The lump may be painless or painful if it has begun to press against nerves or muscles.

The lump from a sarcoma is usually difficult to move around, unlike a common type of lump called a lipoma. A lipoma is an often harmlessTrusted Source overgrowth of fat cells, which a person can usually move around easily by pushing against it.

If someone notices any unfamiliar lumps on their body, they should consult a doctor to rule out more serious causes.

To diagnose STS in the thigh, a doctor usually begins with a physical examination and asks questions about a person’s symptoms and medical history.

The doctor will usually follow with a series of imaging tests and a biopsy to determine whether the lump is cancerous. Imaging tests can also tell a doctor whether STS has spread to lymph nodes or other areas.

Imaging tests may include:

Once a doctor has assessed the results of a person’s imaging tests, they may perform a biopsy.

This involves extracting a small sample of tissue from the tumor. A healthcare professional then analyzes the sample under a microscope.

This procedure can help healthcare professionals determine whether the cells are cancerous and, if so, whether they are from a sarcoma or another type of cancer.

The outlook for any STS depends on various factors, including the type and stage of the cancer.

A 5-year relative survival rate predicts how likely people with the same stage and type of STS are to live for 5 years after diagnosis compared with the overall population.

The survival rates for specific stages of STS are as follows:

SEER stage Stage description 5-year relative survival rate
localizedSTS limits itself to the area where it first developed and has not spread to other tissues.81%Trusted Source
regionalSTS has spread to nearby lymph nodes or structures.56%
distantSTS has spread to other organs or structures. 15%
combinedThis is the average of all SEER stages combined.65%

However, these rates give only a rough idea of the outlook for STS. To get a better idea of a person’s specific outlook, they should consult a doctor.

Learn more about the outlook for soft tissue sarcoma.

What is sarcoma of the thigh?

A sarcoma of the thigh is a type of cancerous tumor that develops in the soft tissue of the thigh. CommonTrusted Source types include fibromyxoid sarcomas, liposarcomas, and solitary fibrous tumors.

What does sarcoma in the thigh feel like?

A lump from STS in the thigh may be painful if the mass is pressing against nerves or muscles, or it may be painless. A person generally cannot move the lump around easily by pressing against it.

Is sarcoma on the thigh curable?

If the STS is low grade and has not spread or a doctor diagnoses it early, a cure may be possible.

If the tumor is large or high grade, it has a greater chance of spreading or recurring.

When should a person worry about a lump on the inner thigh?

If someone notices any unfamiliar lumps on their body, they should always speak with a doctor to rule out more serious causes.

How can a person know if the lump is cancerous?

Only a doctor will be able to rule out cancer through diagnostic tests. However, symptoms of usually cancerous lumps include being hard or unable to move, or have accompanying symptoms such as swelling.

STS most often occurs in the legs, although a person may develop STS in other areas, such as the arms, trunk, internal organs, or neck.

Types of STS that occur in the thigh include fibromyxoid sarcomas, liposarcomas, and solitary fibrous tumors. The most common symptom of STS in the thigh is a lump, which may be either painful or painless.