Epithelioid sarcoma is a rare type of cancer that starts as a growth of cells in the soft tissue. It can happen anywhere on the body. It often starts under the skin on the finger, hand, forearm, knee or lower leg.

Epithelioid sarcoma might cause a small, firm growth or lump under the skin, which is called a nodule. It often does not hurt. There may be one growth or a few growths. Sometimes the growths cause sores on the skin that do not heal.

Epithelioid sarcoma often affects teenagers and young adults. But it can also affect older people. Epithelioid sarcoma tends to grow slowly. It often comes back after treatment.

Epithelioid sarcoma is a type of cancer called a soft tissue sarcoma. These cancers happen in the body's connective tissues. There are many types of soft tissue sarcoma. Soft tissue sarcomas, including epithelioid sarcoma, are not common. It is best to seek care at a cancer center that has experience treating people with sarcoma.

Epithelioid sarcoma can be hard to diagnose. It looks like problems that are much more common. Often health care providers consider those more common problems first. For example, a sore on the skin that is not healing could be mistaken for a skin infection.

Tests and procedures used in diagnosis of epithelioid sarcoma include:

• Imaging tests. Imaging tests take pictures of the body. They can show the location and size of an epithelioid sarcoma. Tests might include X-ray, MRI, CT and positron emission tomography, which is also called a PET scan.
• Getting tissue for testing. A biopsy is a procedure to remove a sample of tissue for testing in a lab. The tissue might be removed using a needle that is put through the skin and into the cancer. Sometimes surgery is needed to get the tissue sample. The sample is tested in a lab to see if it is cancer. Other special tests give more details about the cancer cells. Your health care team uses this information to make a treatment plan.

Surgery is the most common treatment for epithelioid sarcoma. Sometimes other treatments may be used in addition to surgery. Treatment options may include:

• Surgery. Surgery involves removing the cancer and some of the healthy tissue around it. Taking some healthy tissue helps make sure that all the cancer cells are removed. Getting all of the cancer cells lowers the risk that the cancer will come back.
• Radiation therapy. Radiation therapy uses powerful energy beams to kill cancer cells. Radiation therapy is sometimes used before surgery to shrink the tumor. This can make it more likely that all of the cancer will be removed during surgery. Radiation therapy may be used after surgery to kill any cancer cells that might be left.
• Targeted therapy. Targeted therapy uses medicines that attack specific chemicals in the cancer cells that help them to grow. By blocking these chemicals, targeted treatments can cause cancer cells to die. Targeted therapy might be an option if you can't have surgery or if other treatments do not work.
• Chemotherapy. Chemotherapy uses strong medicines to kill cancer cells. Chemotherapy may be an option for treating epithelioid sarcoma that spreads to other parts of the body. It also might be used when surgery is not an option.
• Clinical trials. Clinical trials are studies of new treatments. These studies provide a chance to try the latest treatment options. The side effects may not be known. Ask your health care team whether you might be able to take part in a clinical trial.