What is an epithelioid sarcoma?
An epithelioid sarcoma is a type of soft tissue sarcoma that typically develops in the forearms and hands. Other locations for these cancerous tumors include the legs and feet, chest, abdomen (belly), pelvis, and back.
Epithelioid sarcomas are the most common soft tissue sarcoma found in the hands and arms. But they’re still very rare—doctors diagnose just 150 epithelioid sarcomas in the U.S. each year; these tumors represent less than 1 percent of soft tissue sarcomas. Most people with the disease are in their 20s, 30s, or 40s. Researchers have not yet discovered what causes epithelioid sarcoma, in large part because it’s so rare.
Despite their slow growth and small size—often less than 3 centimeters across—epithelioid sarcomas are aggressive. They start as a firm growth deep within tissues or along tendons. These cancerous tumors can then spread (metastasize) to nearby structures, including blood vessels and the immune system’s lymph vessels and lymph nodes. They can also spread to the lungs.
The sarcoma program at Penn Medicine’s Abramson Cancer Center is home to nationally recognized experts in treating epithelioid sarcoma. They work with our orthopaedic oncology team and other specialists across Penn Medicine to provide you with the highest quality of care. Our surgeons are among the nation’s most experienced when it comes to treating soft tissue sarcomas and can often preserve the function of arms and legs affected by epithelioid sarcoma. With advanced, specialized training, we help you access the most effective treatments for this rare cancer.
Types of epithelioid sarcoma
Doctors divide epithelioid sarcoma into two types, which differ in who they affect, where they form, and how they are treated. The types include:
- Distal epithelioid sarcoma: This form is more common and mostly affects younger adults. It’s usually found as a small soft tissue mass in the hands, forearms, feet, and legs and tends to spread to nearby lymph nodes.
- Proximal epithelioid sarcoma: This more unusual type of tumor tends to be diagnosed in people with an average age of 40. Proximal epithelioid sarcomas typically form in the back, chest, abdomen, and pelvis. They may act more aggressively and grow to 20 centimeters or more across, making them more difficult to treat.
Epithelioid sarcoma signs and symptoms
Since epithelioid sarcomas typically grow slowly without causing pain, most people don't become aware of them right away. However, as the tumor gets larger, you may experience:
- One or more lumps that can continue to grow
- An open skin wound above the lump
- Pain if the tumor forms near a joint or pushes on muscles or nerves
- Swelling
Diagnosing epithelioid sarcoma
An accurate epithelioid sarcoma diagnosis can be challenging and requires a thorough evaluation from an experienced team, like ours. At Penn Medicine, the diagnosis process starts with a discussion of your symptoms and an examination of any lumps. One of our doctors will also check your lymph nodes and lungs.
Imaging tests can provide some information about the tumor, but a definitive diagnosis of epithelioid sarcoma requires an image-guided needle biopsy. During this procedure, one of our radiologists removes a sample of the tumor for study under a microscope. If you are diagnosed with an epithelioid sarcoma of the arms or legs, we may also recommend taking a biopsy of the sentinel lymph node—the first lymph node likely to be affected if the cancer has spread.
Epithelioid sarcoma treatment
At Penn Medicine, we focus on surgically removing the epithelioid sarcoma and any surrounding cancer cells. We may also recommend radiation therapy or chemotherapy depending on the type, size, and location of the tumor, whether the disease has spread, and your age and overall health.
When advanced epithelioid sarcoma isn’t responsive to standard treatment, you may benefit from innovative new approaches, such as epigenetic therapy. Researchers are also exploring the use of immunotherapy, which harnesses the immune system to treat epithelioid sarcoma.
Epithelioid sarcoma care you can trust
When you come to Penn Medicine for epithelioid sarcoma treatment, you’ll receive top care from doctors with specialized training in your specific cancer. We stay up to date on the latest therapies, and our researchers conduct sarcoma clinical trials to help develop new and effective treatments for epithelioid sarcoma. We’re committed to support you through every step, from diagnosis to treatment and follow-up visits.
Rated “exceptional” by The National Cancer Institute
Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.