Diagnosis

Ewing sarcoma diagnosis usually begins with a physical exam to better understand the symptoms you or your child may be experiencing. Based on those findings other tests and procedures may be recommended.

Imaging tests

Imaging tests help your doctor investigate your bone symptoms, look for cancer and look for signs that the cancer has spread.

Imaging tests may include:

• X-ray
• Computerized tomography (CT)
• Magnetic resonance imaging (MRI)
• Positron emission tomography (PET)
• Bone scan

Removing a sample of cells for testing (biopsy)

A biopsy procedure is used to collect a sample of suspicious cells for laboratory testing. Tests can show whether the cells are cancerous and what type of cancer you have.

Types of biopsy procedures used to diagnose Ewing sarcoma include:

• Needle biopsy. The doctor inserts a thin needle through the skin and guides it into the tumor. The needle is used to remove small pieces of tissue from the tumor.
• Surgical biopsy. The doctor makes an incision through the skin and removes either the entire tumor (excisional biopsy) or a portion of the tumor (incisional biopsy).

Determining the type of biopsy needed and the specifics of how it should be performed requires careful planning by the medical team. Doctors need to perform the biopsy in a way that won't interfere with future surgery to remove the cancer. For this reason, ask your doctor for a referral to a team of experts with extensive experience in treating Ewing sarcoma before the biopsy.

Testing the cancer cells for gene mutations

A sample of your cancer cells will be tested in the lab to determine which DNA changes are present in the cells. Ewing sarcoma cells usually have changes in the EWSR1 gene. Most often the EWSR1 gene becomes fused with another gene called FLI1, creating a new gene called EWS-FLI1. Testing the cancer cells for these gene changes can help confirm your diagnosis and give your doctor clues about the aggressiveness of your disease.