Just a Bump or Something More? What You Need to Know About Sarcomas

A lump beneath the skin is usually harmless. Persistent bone pain may be blamed on an old injury or arthritis. But in rare cases, these symptoms can signal a sarcoma—a complex group of cancers for which an accurate diagnosis and carefully planned treatment are especially important.

Sarcomas can begin almost anywhere in the body and encompass dozens of distinct diseases. Because they are uncommon, many people have never heard of them before receiving a diagnosis.

What Is a Sarcoma?

Most familiar cancers begin in the cells lining organs or glands, such as those in the breast, lung, colon or prostate. Sarcomas develop in the body’s connective and supporting tissues.

“Sarcomas are a rare group of malignant tumors and are different from the more typical cancers that arise from squamous cells or glandular cells,” says Harold Huss, D.O., a surgical oncologist with Lynn Cancer Institute at Boca Raton Regional Hospital, part of Baptist Health. “They can come from muscle, fat tissue, fibrous tissue, blood vessels, bone, cartilage and many other tissues.”

According to Dr. Huss’s colleague, Michael Kasper, M.D., a radiation oncologist and medical director of radiation oncology at Lynn Cancer Institute, sarcomas are generally divided into two categories: soft-tissue sarcomas and primary bone sarcomas.

“Soft-tissue sarcomas can originate in muscles, tendons, fat, nerves, blood vessels and tissues surrounding joints. They may develop in the arms, legs, trunk, head and neck or deep within the abdomen,” Dr. Kasper says.

There are approximately 80 to 100 histologic subtypes of sarcoma, he adds. Liposarcoma begins in fat cells, leiomyosarcoma in smooth muscle and angiosarcoma in blood or lymph vessels. Gastrointestinal stromal tumors, known as GISTs, arise in the digestive tract. Bone sarcomas include osteosarcoma, chondrosarcoma and Ewing sarcoma.

How Common Are Sarcomas?

The American Cancer Society estimates that 13,910 soft-tissue sarcomas will be diagnosed in the United States in 2026 and that 5,400 people will die from them. An additional 4,110 primary cancers of the bones and joints are expected to be diagnosed, with approximately 2,210 deaths. Combined, that represents roughly 18,000 diagnoses and 7,600 deaths annually due to sarcomas.

“Sarcomas are fairly rare, accounting for about 1 percent of malignancies in the U.S.,” Dr. Kasper notes. “The prognosis depends on the type of sarcoma, when it is found, whether it is early or late and whether it has spread.”

Some sarcomas are relatively slow-growing and can be cured with surgery. Others are aggressive and may spread, most frequently through the bloodstream to the lungs. Outcomes also depend on the tumor’s size, grade, location and response to treatment.

Malignant Melanotic Nerve Sheath Tumor

One particularly rare and aggressive form of sarcoma is malignant melanotic nerve sheath tumor (MMNST), according to Dr. Huss.

Typically seen in young adults, MMNST arises in peripheral or cranial nerves and often has melanocytic characteristics, meaning that it shows properties or behavior associated with the specialized skin cells responsible for producing melanin, the pigment that gives skin, hair and eyes their color.

“MMNSTs have a high recurrence rate and often metastasize to other parts of the body,” Dr. Huss adds.

Symptoms That Should Be Evaluated

A gradually enlarging lump is the most common warning sign of a soft-tissue sarcoma. It is often painless, which can make it easy to dismiss, according to Dr. Kasper.

“The most common presentation is a painless mass,” he says. “Most of the time, patients say, ‘I have had this bump for a long time, and now it is growing. What do you think?’”

The National Cancer Institute (NCI) advises people to see a physician for an unexplained lump or swelling, particularly if it is growing. Abdominal sarcomas may produce few symptoms until they become large enough to press on organs, nerves or blood vessels. At that point, they may cause pain, fullness, digestive problems or difficulty breathing.

Bone sarcomas may cause persistent bone pain, often worsening at night, as well as swelling or reduced movement near the affected area.

Dr. Huss says a mass is particularly concerning when it is enlarging, painful, deep beneath the muscle’s connective tissue or larger than about 5 centimeters—roughly the size of a golf ball. A mass that returns after being removed also warrants prompt evaluation.

“If you see or feel a lump or mass, even if it is painless, bring it to the attention of your physician,” he advises. “Outcomes are much better if these tumors are caught early.”

Who Is at Risk for Sarcoma?

Most sarcomas develop without a clearly identifiable cause, according to Dr. Huss. They may occur at any age, although particular subtypes are more common in children, adolescents or older adults.   

Known sarcoma risk factors include:

·      Previous radiation therapy

·      Longstanding lymphedema (swelling, most often in the arms or legs, from a buildup of lymph fluid)

·      Exposure to certain chemicals, including vinyl chloride and arsenic

·      Inherited conditions such as Li-Fraumeni syndrome, neurofibromatosis type 1, hereditary retinoblastoma and familial adenomatous polyposis

Because sarcomas are uncommon and there is no recommended routine screening test for the general population, being aware of any unusual or changing symptoms is essential, Dr. Huss adds.

Sarcoma Treatment Requires Careful Planning

Treatment of sarcomas is individualized and may involve surgery, radiation therapy, chemotherapy, targeted drugs, immunotherapy or observation. Ordinarily, the tumor should be imaged and biopsied before anyone attempts to remove it.

“If there is concern that a mass may be a sarcoma, the answer is not to just remove it but to biopsy it and find out what it is before tackling it,” Dr. Huss says.

An unplanned operation performed under the assumption that a mass is benign can leave cancer cells behind, complicate subsequent surgery and affect function. Sarcoma pathology is also unusually complex, making review by a pathologist with specific soft-tissue expertise important.

Surgery is often the recommended treatment for localized sarcoma. Depending on the subtype and location, radiation may be used before or after surgery to reduce the chance of the tumor returning.

“There was a major paradigm shift in the curative management of sarcomas,” Dr. Kasper says. “The standard treatment was once amputation of the diseased limb. Then it was discovered that adding radiation to a wide surgical excision could produce essentially the same results as amputation. You can imagine how many limbs have been saved in the decades since.”

When appropriate, radiation before surgery can permit a lower dose and smaller treatment area, Dr. Kasper notes. Lynn Cancer Institute also offers proton therapy, which can help limit radiation exposure to nearby organs in selected tumors of the abdomen, chest, head or neck.

The Value of a Dedicated Sarcoma Team

At Lynn Cancer Institute, sarcoma cases are reviewed through a weekly multidisciplinary conference involving surgical, medical and radiation oncologists, along with radiologists, pathologists, psychosocial specialists, dietitians and other professionals.

“We bring them together, discuss the patient’s case and come up with the best recommendations,” Dr. Kasper says. “Patients are not bouncing around from one physician to the next while the tumor is growing.”

That collaboration is important because the order and technique of treatment can affect tumor control and healing, not to mention the patient’s long-term function and quality of life.

“It is very clear that, with sarcomas, experience really makes a difference,” Dr. Kasper says.

Dr. Huss agrees, adding that there is also “strong evidence that multidisciplinary treatment—including surgery, chemotherapy and radiation—offers the best outcomes” for patients diagnosed with sarcoma.

He emphasizes that specialized care remains important after treatment because some sarcomas can recur years later.

“Anyone with a sarcoma should consider going to a sarcoma center of excellence such as Lynn Cancer Institute,” he says. “Alternative treatments may just delay care and allow the disease to progress. We not only treat sarcoma patients, but we also follow them for the rest of their lives.”

Click here for more information about the sarcoma treatments and specialists available at Lynn Cancer Institute.