You twist your knee in a game. You get a hard tackle, and a lump comes up on your thigh. Your shoulder still hurts weeks after you pulled a muscle. These problems are usually caused by a pulled muscle, a bruise, or a small tear. Usually, rest, ice, and a few days off will heal them.
Sometimes a lump or a deep ache is not a sports injury. Sarcoma is a rare cancer that can mimic the sorts of symptoms you’d put down to training or a fall. Understanding the early symptoms of sarcoma can help you differentiate between a common strain and a warning sign you shouldn’t ignore.
This guide teaches you what sarcoma is, how to tell a soft tissue lump from an injury, the bone cancer warning signs to watch out for, and when you should make an appointment with your doctor.
What Is Sarcoma?
Sarcoma is a cancer of connective tissues. These tissues are bone, muscle, fat, cartilage, nerves, and blood vessels. Doctors split sarcoma into two main groups.
Soft tissue sarcoma is a cancer that grows in muscle, fat, tendons, nerves, or blood vessels. The American Cancer Society estimates that about 13,000 new cases are diagnosed in the United States each year.
Bone sarcoma begins in the bone itself. Osteosarcoma and Ewing sarcoma are the two most common types. Both are more common among young adults and teenagers.
Sarcoma is still rare. Combined, the two types account for about 1 percent of cancer in adults and nearly 15 percent of cancer in children. Doctors see so few cases, and the early symptoms look so ordinary that many people wait months to get a proper diagnosis.
Why Sarcoma Gets Mistaken for a Sports Injury
Athletes and active individuals push their bodies to the max. Aches, swelling, and lumps are part of the package. You see a new lump, and your first thought is a bruise or a pulled muscle. Not cancer. That is an understandable instinct, for injuries are common and sarcoma is not.
The overlap is deep. Soft tissue sarcoma often feels like a hard lump under the skin, like the one you get after a hard blow. Bone sarcoma causes deep pain in the limb, like shin splints or a stress fracture. Young athletes present complaints of bone pain and are sent to physical therapy, but the real problem is hidden.
The time from the appearance of the first symptom to diagnosis averages several months for many patients, a 2017 study in the journal Sarcoma found. Some of the delays are patients waiting for the problem to resolve it on their own. Part of it is the doctors treating it as a sports injury first.
The lesson is simple. You don't have to freak out over every bump or ache. You do need to know what signs point away from a normal injury and toward something worth checking out.
Soft Tissue Lump vs Injury: How to Tell the Difference
A lump from an injury feels different in a few ways from a lump from a soft tissue sarcoma. Use these points to compare what you see on your own body.
Size: Generally, a bruise or hematoma injury lump will shrink in size as your body heals over a period of two to three weeks. There's a lump of sarcoma coming up. A lump bigger than a golf ball, around 5 centimeters, should be taken seriously, especially if it grows bigger each week.
Pain: Cancer is often thought to be painful. Soft tissue sarcomas are usually painless in the early stages. A painless lump is a false comfort. You think a serious problem will hurt you. However, an injured lump will usually be tender and will get better as it heals.
Location: Sarcoma lumps tend to be deep, under the muscle layer, rather than just under the skin. A bump deep in your thigh, groin, or the back of your leg is more concerning than a small, movable bump just below the surface.
Movement: A benign lump, such as a lipoma, usually moves easily under your fingers. Sarcoma often feels stuck, attached to the surrounding tissue.
Healing time: An injury needs two to six weeks to heal, and a strain or bruise needs to heal. Make a check if the lump stays the same or grows during this window.
If you have any soft tissue lump that is over 5 centimeters, deep, growing, or painful, you should have an ultrasound or MRI. Either of these conditions is a reason to see your doctor.
Bone Cancer Warning Signs
Bone sarcoma presents itself in different ways than a soft tissue lump. Parents of young athletes and athletes themselves should be aware of these patterns, since the pain begins from inside the bone.
Pain getting worse at night: Ordinary muscle soreness goes away with rest. Bone cancer pain is often the reverse. Many patients describe a deep ache that awakens them at night or worsens with rest. One of the most obvious warning signs of bone cancer is pain in a bone at night.
Pain not tied to activity: A stress fracture or shin splint will hurt when you run and will go away when you stop. Bone sarcoma pain is constant whether you move or rest and get worse over weeks.
Swelling over a bone: Hard swelling over a joint (knee, shoulder, or upper arm) suggests possible bone involvement. Osteosarcoma most commonly occurs in the knee in adolescents during a growth spurt.
A bone breaking easily: Cancer eats at the inside of the bone. A fracture from a minor knock, the kind you'd expect to shrug off, can sometimes be a sign of a tumor that has already thinned the bone from the inside. The doctors call this a pathological fracture.
Reduced range of motion: If you can’t bend a joint, or a limb feels stiff, and there’s no obvious injury, it’s worth a look.
Osteosarcoma is most common among people between the ages of 10 and 30 years and again in older adults over 60 years of age. If your teen has persistent pain in the bones around the knee or shoulder that doesn’t improve with rest, don’t just assume growing pains. Discuss your imaging with your doctor.
Other Early Symptoms of Sarcoma You Should Not Overlook
Other than lumps and bone pain, sarcoma can also be seen with signs you wouldn’t associate with cancer at first.
A lump in the abdomen: Sarcomas that arise in the abdomen, such as retroperitoneal sarcoma, often grow to a large size before causing symptoms. Pay attention to a feeling of fullness, unexplained bloating, or a lump that you can feel when you press on your stomach.
Blood in stool or vomit: Gastrointestinal stromal tumors (GISTs) are a type of sarcoma in the digestive tract. Sometimes they can bleed. Dark stool or unexplained anemia indicates a check-up.
Unexplained weight loss and fatigue: Sarcoma is one of many cancers that can cause you to lose weight without trying and feel tired all the time.
Persistent cough or breathing trouble: Sarcoma sometimes spreads to the lungs. If you have a cough that lasts weeks along with any of the above signs, you need to be looked at.
These more general symptoms are rarely a sign of sarcoma. But a growing lump, or deep bone pain, paints a picture worth showing your doctor.
When to See a Doctor
Use this check list. If you see any of the below, book an appointment.
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A lump bigger than 5 centimeters, or about the size of a golf ball.
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A lump that enlarges over a few weeks rather than shrinking.
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It is a deep lump, beneath the muscle, not near the surface of the skin.
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Bone or joint pain that is worse at night or does not get better with rest.
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The swelling of a bone lasted over 2 weeks.
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A rest from a minor injury.
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Any lump or pain with weight loss, fatigue, or night sweat.
Trust your own body reading. If a problem you thought was sport-related continues to increase or hurt beyond the normal healing window, get imaging. Early diagnosis makes a difference. The American Cancer Society reports that the five-year survival rate for localized soft tissue sarcoma is about 81 percent, but it decreases significantly when the cancer spreads. Your best chance is if you catch sarcoma before it spreads.
How Doctors Diagnose Sarcoma
The road ahead is familiar, and the fear of asking for help is lower. This is generally what happens after you raise a concern.
Physical exam: Your doctor will feel the lump, examine its size and depth, and ask questions about your history.
Imaging: Ultrasound provides an initial view of a soft tissue lump. The MRI gives a very detailed picture of the soft tissue and shows the outline of the tumor. Bone X-ray, followed by MRI or CT.
Biopsy: A specialist removes a small piece of tissue and sends it to a lab. This confirms whether the growth is benign or sarcoma and exactly what type.
Referral to a sarcoma center: Sarcoma is rare, and treatment is best done at a center with a dedicated sarcoma team. Research has shown that patients treated in specialist centers do better than patients treated in general hospitals.
If the biopsy confirms the diagnosis, ask your doctor to refer you to a sarcoma specialist. You have the right to be treated by a team that treats these cancers every week.
Reducing Your Risk and Staying Alert
There is no proven lifestyle change to prevent sarcoma, because most cases have no known cause. However, a few factors do raise risk, and awareness helps.
Prior radiation therapy increases the risk of sarcoma in the treated field years later.
Some inherited conditions, like Li-Fraumeni syndrome and neurofibromatosis, increase risk.
Swelling in a limb is sometimes a side effect of a rare type of sarcoma.
Prevention is still limited, so early detection is the most important thing. Check out any new lumps using this guide. Give an injury time to heal. If it doesn't get better, do something.
Key Takeaways
Sarcoma is rare, but the later the diagnosis, the worse the outcome. Most bumps and aches are normal injuries, so you don't need to worry about every bruise. A lump larger than 5 centimeters, one that is growing week by week, one that is deep under muscle, or bone pain that is worse at night, are not normal sports injuries. If you see these signs, don’t hesitate to tell your doctor to order an imaging. The sooner you act, the better your chances for a good recovery.
Frequently Asked Questions
How quickly does a sarcoma lump grow?
The rate of growth varies by type. Certain soft tissue sarcomas grow slowly over months, while others grow within weeks. If the lump is getting bigger over two to four weeks, instead of getting smaller like a bruise, that is a good time to order imaging.
Is sarcoma always painful?
No. In fact, early soft tissue sarcoma usually has no pain at all. A painless lump is false reassurance. Bone sarcoma, however, usually produces a deep ache that gets worse at night. You may not have pain even if you have sarcoma.
What size of lump should I worry about?
A lump bigger than 5 centimeters, the size of a golf ball, is worth getting checked out by a professional. Depth, growth, and firmness raise concern even further. A small, soft, movable bump near the surface of the skin is much less of a risk, but you should also have a growing bump checked out.
Can a sarcoma start as a sports injury?
No! An injury does not cause sarcoma or turn into one. The early symptoms overlap, so the two are confused, and a person sometimes notices a lump after a knock draws attention to the area. The injury did not cause the tumor.
How do doctors differentiate a benign lump from a sarcoma?
Doctors study the lump using imaging techniques like ultrasound or MRI and confirm it with a biopsy. A biopsy is a definitive test to determine whether growth is benign or cancerous. The tissue is examined under a microscope.
Who Gets Sarcoma?
Soft tissue sarcoma occurs at any age but is most common in adults over age 50. Bone sarcomas such as osteosarcoma and Ewing sarcoma are more common among teenagers and young adults during their growth years. Anyone with a suspicious lump, of any age, should be checked.
What is the survival rate for sarcoma?
The American Cancer Society says the five-year survival rate for soft tissue sarcoma that is found before it has spread is about 81 percent. The outcomes are worse once the cancer has spread to other parts of the body, and that is why it is so important to diagnose it early.
Do I see a specialist or my regular doctor first?
Begin with your regular doctor, who will look at the lump and order the first imaging. Results suggest referral of sarcoma to a specialized sarcoma center. Specialist teams tend to have better results for the patients they treat.
Image Credit: The Yuri Arcurs Collection at FreePik
