Epithelioid sarcoma can be hard to diagnose. It looks like problems that are much more common. Often healthcare professionals 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 the 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 healthcare team uses this information to make a treatment plan.