What is a clear cell sarcoma?
A clear cell sarcoma (CCS) is a cancerous tumor that typically grows just under the skin. CCS tumors are usually found near muscle coverings called sheaths. They can also occur near tendons, the connections between muscles and bones.
The most common locations for CCS are the legs, ankles, hands, and feet. Tumors occasionally form in the head and neck, genitals, gastrointestinal (GI) tract, chest, abdomen (belly), pelvis, and back. CCS may also occur as an unusual pediatric kidney cancer called clear cell sarcoma of the kidney.
A type of soft tissue sarcoma, clear cell sarcomas are extremely rare. When they occur, they mainly affect people in their 20s, 30s, or 40s. The tumor can spread to other parts of the body or return after treatment.
Penn Medicine’s sarcoma care team is highly experienced in CCS. We can accurately diagnose this type of sarcoma and provide timely treatment. Specialists from several areas come together to provide your care, including surgeons, oncologists, specialized radiologists, and others. After the tumor is removed, we continue to monitor you over the long-term and provide immediate treatment if the cancer returns. You can trust our experts to help you effectively manage CCS.
Signs and symptoms of clear cell sarcoma
Clear cell sarcoma may not cause symptoms right away. But as the tumor grows larger, you might experience:
- A lump under your skin that may cause pain, swelling, or tenderness
- Fatigue
- Night sweats
- Unexplained weight loss
- Rarely, ulcers (open wounds) on the skin
What causes clear cell sarcoma?
Clear cell sarcomas form because of changes in chromosomes—the structures inside cells that are made of DNA. With clear cell sarcoma, two genes in DNA swap places and recombine. The new genes function differently than they should and appear to promote cancer. Researchers don’t yet know why the chromosomal swap happens with CCS. This gene change (also called a variant or mutation) cannot be passed down to children.
For other soft tissue sarcomas, gene changes related to cancer are sometimes caused by exposure to certain chemicals, previous medical treatments, or unusual inherited genetics. It’s unclear if any of these risk factors apply to clear cell sarcoma.
Doctors currently do not know of any steps you can take to reduce your risk of developing a clear cell sarcoma.
Tests that diagnose clear cell sarcoma
The most accurate diagnosis of a clear cell sarcoma comes from an experienced cancer team like the one at Penn Medicine. Because the disease has similarities to the skin cancer melanoma, the shared features require a thorough evaluation by an experienced team who knows what to look for with a suspected tumor. In fact, the diseases are so similar that CCS was previously called “malignant melanoma of soft parts.”
To diagnose a potential clear cell sarcoma, our team starts by examining any lumps and asking you about symptoms you’ve experienced. Imaging scans then provide the team with more information. Magnetic resonance imaging (MRI) can show the size of the tumor, how far it has grown, and which tissues it has affected. Computed tomography (CT) can show whether cancer has spread and, if so, to which locations.
To confirm a diagnosis, our specialized radiologists perform an image-guided needle biopsy. We take a sample of tumor tissue, study it under a microscope, and run lab tests on it. By testing for genetic changes, those lab tests can confirm whether a tumor is clear cell sarcoma or something else.
Information from the exam, scans, and biopsy helps us stage clear cell sarcoma. Staging is a more detailed description and categorization of the cancer that helps guide our treatment planning, for the most effective approach.
Strategies to treat CCS
When clear cell sarcoma has not spread, our treatment focuses on surgically removing the tumor in one piece, along with a small border of healthy tissue to ensure all the cancer is removed.
To lower the chances of the cancer returning, we may recommend radiation therapy before or after surgery. Receiving radiation therapy before surgery can also help reduce the side effects of treatment.
Clear cell sarcoma often returns after treatment, either in the same area or in other parts of the body. After you complete treatment, our team will recommend regular follow-up appointments to monitor for signs that the cancer has returned and begin treatment promptly if needed.
Penn Medicine continues to explore new ways to treat soft tissue sarcomas through innovative research. Our world-class cancer specialists combine leading-edge therapies with compassionate, personalized care to support even the most challenging cases of clear cell sarcoma.
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.