Overview

Epithelioid sarcoma is a rare, slow-growing type of soft tissue cancer. Most cases begin in the soft tissue under the skin of a finger, hand, forearm, lower leg or foot, though it can start in other areas of the body.

Typically, epithelioid sarcoma starts as a small firm growth or lump that's painless. It usually starts out as a single growth, but multiple growths may occur by the time a person seeks medical help. Sometimes this sarcoma appears as ulcers that don't heal, looking like open wounds over the growths.

The classic form (distal-type) of epithelioid sarcoma mainly occurs in teenagers and young adults. A rarer form, called large-cell (proximal-type) epithelioid sarcoma, tends to be more aggressive and mainly affects adults.

Epithelioid sarcoma tends to have a high rate of recurrence and can spread to other areas. So if epithelioid sarcoma is suspected, it's best to seek care at a comprehensive cancer center that sees more cases of soft tissue sarcoma to ensure proper diagnosis and treatment, and to help prevent the cancer from recurring.

Diagnosis

Epithelioid sarcoma can be difficult to diagnose because it may be confused with other conditions that have similar signs. For example, an ulcer on the skin that isn't healing could be mistaken for a skin infection.

Tests and procedures used in diagnosis of epithelioid include:

• Imaging. Magnetic resonance imaging (MRI) is typically the method of imaging because of the level of detail it provides. Sometimes other imaging tests, such as computed tomography (CT) or positron emission tomography (PET), may be used.
• Biopsy. The doctor performs a biopsy using a long, thin needle to remove a sample of the suspected sarcoma or a larger lump for testing in a lab. Sometimes a biopsy sample is removed during surgery. A pathologist analyzes the sample to determine whether it's cancer, and if so, the type and whether it's aggressive.

Treatment

Surgery is the most common treatment for epithelioid sarcoma, but other treatments may be used in addition to surgery.

• Surgery. Surgery generally involves removing the cancer and a margin of healthy tissue surrounding it to help prevent recurrence. In severe cases, depending on the size, depth and location of the cancer, there's a rare possibility that part of the affected limb would need to be amputated, but surgeons try their best to avoid doing this.
• Radiation therapy. Radiation therapy uses high-energy beams, such as X-rays or protons, to kill cancer cells. Radiation therapy is sometimes used before surgery to shrink the tumor and reduce the risk of the cancer returning, and after surgery to help reduce the risk of recurrence.
• Chemotherapy. Chemotherapy uses drugs to kill cancer cells. Chemotherapy appears to be less effective in treating epithelioid sarcoma compared with other cancers, though it's sometimes used in addition to surgery or when the cancer has spread.
• Clinical trials. Clinical trials are studies of new treatments. These studies provide a chance to try the latest treatment options, but the risk of side effects may not be known. Targeted cancer therapies — drugs or other substances that target certain molecules to block cancer growth — show promise in the treatment of epithelioid sarcoma. Ask your doctor about the availability of clinical trials, including the potential risks and benefits.