A lump that won't go away. A sore muscle that never seems to heal. Swelling that you assume is related to exercise or a minor injury.
Most of the time, these symptoms are not cancer. But in very rare cases, they can be signs of sarcoma, a group of cancers that develop in the body's connective tissues, including muscles, fat, bones, the lining of joints or blood vessels.
Because sarcoma is uncommon, many people have never heard of it until they or someone they love receives a diagnosis. That unfamiliarity can also contribute to delays in seeking care, especially among younger people who may not consider cancer a possibility.
Sarcoma can affect people of any age
Sarcomas account for about 1% of all cancers, making them one of the rarest cancer types. More than 70 subtypes exist, with some forms being more common in children and adolescents while others occur more often in adults.
Soft tissue sarcomas, which predominantly affect adults, are the most common form. The American Cancer Society estimating that 13,910 new cases will be diagnosed in 2026. Bone sarcomas are less common.
Unlike many cancers, sarcoma does not have a routine screening test. Early detection depends on recognizing symptoms and seeking medical evaluation when something doesn't seem right. But that is challenging with sarcoma, as it often doesn't cause obvious symptoms early on, and there are very few known risk factors.
Symptoms that are easy to dismiss
Certain bone sarcomas are diagnosed more frequently in children, teenagers and young adults, while soft tissue sarcomas occur across adulthood. Persistent or unexplained symptoms shouldn't be dismissed simply because of a person's age.
Soft tissue sarcomas may first appear as a painless lump that gradually increases in size. They can appear in any part of the body, but most commonly in the arms or legs. But because these masses can resemble benign growths, many people assume they are harmless and delay having them evaluated.
"If you notice a lump that was not there the month before, that would be a good reason to seek care," said Dr. Nickolas Reimer, of the Northside Hospital Cancer Institute Bone & Soft Tissue Program.
Bone sarcomas, however, "are almost always painful," Dr. Reimer said. But they may initially be mistaken for a sports injury, particularly in younger, active individuals. The pain often becomes constant over time, worsens with activity and may be accompanied by swelling near the pain point.
In other cases, sarcomas may not cause symptoms until they press on nerves, organs, or muscles.
"If you have pain that cannot be explained by some type of injury or joint-related dysfunction, like arthritis," it is time for an evaluation, Dr. Reimer said. Especially if the pain does not respond to pain relievers.
Early evaluation is especially important because sarcoma outcomes are closely tied to how advanced the cancer is when it is diagnosed. When sarcoma is found before it has spread, treatment is often more successful. As the disease progresses, treatment becomes more complex and survival rates decline.
Most people have no known risk factors
For many patients, a sarcoma diagnosis comes without warning.
Although previous radiation therapy, chronic lymphedema, certain chemical exposures and rare inherited genetic conditions can increase risk, most people who develop sarcoma have no identifiable cause.
Researchers estimate that approximately 5% to 10% of sarcomas are hereditary, although the percentage may be higher for certain subtypes. More than 30 genes have been linked to an increased risk of sarcoma.
One inherited condition, Li-Fraumeni syndrome, significantly increases a person's lifetime risk of developing several cancers, including sarcoma.
For people with a personal or family history that suggests an inherited cancer syndrome, genetic counseling and testing may help guide treatment decisions and identify screening recommendations for both patients and their relatives.
Specialized care matters
Survival rates and quality of life improve when cancer care is tailored to the individual rather than taking a generalized approach. At Northside Hospital Cancer Institute, orthopedic oncologists, medical oncologists, radiation oncologists, radiologists, pathologists and genetic counselors work together to develop an individualized treatment plan for each patient.
Evaluation for sarcoma typically involves imaging studies such as X-rays, MRI, CT or PET/CT scans, followed by a carefully planned biopsy when appropriate. Treatment may include surgery, radiation therapy, chemotherapy, targeted therapy or a combination of approaches.
The bottom line? Most lumps and persistent aches are not sarcoma. But do not ignore rapid growth of a soft tissue mass or deep, unrelenting bone pain without history of trauma or injury, Dr. Reimer said. Early evaluation can make an important difference.
