7 Key Signs of Soft Tissue Sarcoma You Should Never Ignore

Soft tissue sarcoma is a rare type of cancer that develops in the soft tissues of the body, including muscles, fat, blood vessels, nerves, tendons, and the lining of joints. This malignancy can occur anywhere in the body, but most commonly affects the arms, legs, and abdomen. Accounting for less than 1% of all adult cancers, soft tissue sarcomas often go undetected in their early stages because symptoms can be subtle or mistaken for less serious conditions.

Early detection of soft tissue cancer is crucial for successful treatment outcomes. Understanding the warning signs can help you identify potential problems and seek medical attention promptly. While many lumps and bumps are benign, knowing what to look for can make a significant difference in catching this disease early when treatment is most effective.

In this comprehensive guide, we’ll explore the seven key symptoms of soft tissue sarcoma, what causes this condition, and answer frequently asked questions to help you better understand this rare but serious disease.

1. A Noticeable Lump or Swelling

The most common and often first symptom of soft tissue sarcoma is the presence of a painless lump or swelling beneath the skin. This mass typically:

• Appears gradually and grows slowly over weeks or months
• Feels firm or hard to the touch
• May be located deep within soft tissue, making it less noticeable initially
• Can range in size from very small to several inches in diameter
• Often doesn’t cause pain in the early stages

Many people dismiss these lumps as harmless cysts, lipomas (fatty tumors), or the result of an injury. However, any lump that persists for more than two weeks, continues to grow, or exceeds 5 centimeters (about 2 inches) in diameter should be evaluated by a healthcare professional. Lumps located deep in the body, particularly those in the abdomen or retroperitoneum (the area behind the abdominal cavity), may not be noticeable until they’ve grown quite large.

It’s important to note that while most lumps are not cancerous, soft tissue sarcomas typically present as a growing mass, making medical evaluation essential for proper diagnosis.

2. Pain or Tenderness in the Affected Area

While soft tissue sarcomas often begin as painless lumps, pain and tenderness can develop as the tumor grows and begins to:

• Press against nearby nerves, causing nerve pain or radiating discomfort
• Compress blood vessels, leading to aching or throbbing sensations
• Invade surrounding muscles or organs
• Stretch the tissue capsule surrounding the tumor

The pain associated with soft tissue sarcoma can vary significantly from person to person. Some individuals experience a dull, persistent ache, while others may feel sharp, shooting pains, particularly if nerves are involved. The pain might be intermittent at first but tends to become more constant as the tumor enlarges.

Pain may worsen with activity or pressure on the affected area. For sarcomas located in the limbs, pain might increase during movement or exercise. Abdominal sarcomas can cause chronic abdominal pain or discomfort that may be mistaken for gastrointestinal issues.

It’s worth noting that the absence of pain doesn’t mean a lump is harmless. Many soft tissue sarcomas remain painless even as they grow, which is why any persistent or growing mass warrants medical attention regardless of pain level.

3. Limited Range of Motion or Functional Impairment

As a soft tissue sarcoma grows, it can interfere with normal body function, particularly when located near joints or in areas crucial for movement. Patients may experience:

• Difficulty moving a limb through its full range of motion
• Stiffness in nearby joints
• Weakness in the affected limb or area
• Inability to perform previously easy tasks
• Changes in gait or posture to compensate for the mass

When sarcomas develop near joints like the knee, hip, shoulder, or elbow, they can physically block normal joint movement or cause pain that limits mobility. For example, a sarcoma in the thigh might make it difficult to fully bend or straighten the knee, while one in the shoulder region could restrict arm movement.

In the hands or feet, these tumors can affect fine motor skills and grip strength. Patients might notice difficulty with activities like writing, buttoning clothes, or walking normally. The functional impairment typically worsens gradually as the tumor grows, though sometimes it may seem to appear suddenly when the mass reaches a critical size.

These limitations can significantly impact daily life and are often the symptom that finally prompts people to seek medical care, especially if they’ve been ignoring a growing lump.

4. Swelling or Inflammation Around the Mass

As soft tissue sarcoma progresses, the area surrounding the tumor may show visible signs of swelling and inflammation. This occurs because:

• The tumor disrupts normal tissue architecture
• Blood flow and lymphatic drainage become compromised
• The body’s immune system responds to the abnormal growth
• Pressure builds up in surrounding tissues

The swelling may extend beyond the actual tumor itself, making the affected limb or area appear noticeably larger than the opposite side. The skin over the mass might appear stretched, shiny, or tight. In some cases, visible veins may become more prominent on the surface as the tumor affects normal blood circulation.

The inflammation can cause the area to feel warm to the touch, and the skin may appear slightly reddened, though this is less common than with infections or other inflammatory conditions. Some patients experience edema (fluid accumulation) in the affected limb, particularly in sarcomas of the legs or arms, which can cause the entire limb to swell.

This type of swelling differs from the localized bump of the tumor itself and indicates that the growth is affecting surrounding tissues and potentially the vascular or lymphatic systems.

5. Numbness or Tingling Sensations

When a soft tissue sarcoma develops near or compresses peripheral nerves, it can cause neurological symptoms including:

• Numbness in the affected area or regions served by the compressed nerve
• Tingling or “pins and needles” sensations
• Burning feelings along the nerve pathway
• Decreased sensitivity to touch, temperature, or pain
• Radiating sensations that travel along the limb

These neurological symptoms occur because the tumor physically presses against nerve fibers, disrupting their normal function. The specific pattern of numbness or tingling depends on which nerves are affected. For instance, a sarcoma in the thigh might compress the femoral nerve, causing symptoms down the front of the leg, while one in the armpit could affect the brachial plexus, leading to symptoms throughout the arm and hand.

In some cases, patients experience paresthesias (abnormal sensations) before they even notice a visible lump, especially if the tumor is growing deep within soft tissue. These symptoms might be intermittent at first, occurring only with certain positions or movements, but typically become more constant as the tumor grows.

Nerve compression can also lead to muscle weakness in areas controlled by the affected nerve, further impacting function. Any persistent numbness, tingling, or weakness should be evaluated promptly, as prolonged nerve compression can potentially lead to permanent damage.

6. Abdominal Symptoms (for Internal Sarcomas)

Soft tissue sarcomas that develop within the abdomen or retroperitoneum often remain undetected until they grow quite large because there’s more space for them to expand before causing symptoms. When symptoms do appear, they may include:

• Persistent abdominal pain or discomfort
• Feeling of fullness or bloating, even after small meals
• Visible abdominal swelling or distension
• Nausea or vomiting
• Changes in bowel habits, including constipation
• Difficulty eating or early satiety
• Unintended weight loss

Internal soft tissue cancer can press against the stomach, intestines, or other abdominal organs, causing these gastrointestinal symptoms. A large retroperitoneal sarcoma might push the stomach forward, reducing its capacity and making patients feel full quickly. Compression of the intestines can lead to constipation or, in severe cases, bowel obstruction.

Some patients notice a palpable mass in their abdomen that they or their doctor can feel during examination. Others might see asymmetric abdominal swelling, where one side of the belly appears more prominent than the other.

Because these symptoms are common to many gastrointestinal conditions, abdominal sarcomas are often misdiagnosed initially. However, symptoms that persist despite treatment for common conditions, or a palpable abdominal mass, should raise suspicion for a more serious underlying cause.

Blood in the stool or urine can occasionally occur if the tumor affects the intestines or urinary system, though this is less common.

7. Systemic Symptoms

As soft tissue sarcoma advances, particularly if it grows large or spreads, patients may experience general systemic symptoms that affect overall health:

• Unexplained fatigue and weakness
• Unintentional weight loss
• Low-grade fever that comes and goes
• Night sweats
• Loss of appetite
• General feeling of being unwell (malaise)

These constitutional symptoms occur because cancer affects the body’s metabolism and immune system. The tumor consumes nutrients and energy, and the immune system’s ongoing response to the malignancy can cause fatigue and other systemic effects.

Weight loss in soft tissue sarcoma patients can result from several factors: decreased appetite due to the tumor’s effects, increased metabolic demands from the cancer, or mechanical effects if an abdominal tumor interferes with eating and digestion. Loss of 10 pounds or more without trying to lose weight is considered significant and warrants medical evaluation.

Fever associated with soft tissue sarcoma is typically low-grade (slightly elevated) rather than high fever, and it may be intermittent. This occurs due to substances released by the tumor or the body’s immune response to it.

Night sweats severe enough to soak through sleepwear and bedding can occur, though this is more common with some other types of cancer.

It’s important to recognize that these systemic symptoms are generally late signs, appearing after the tumor has grown substantially or spread. However, they can also be caused by countless other conditions, many of them benign. The key is paying attention when these symptoms occur together, persist for more than a few weeks, or occur alongside a noticeable lump or mass.

Main Causes and Risk Factors of Soft Tissue Sarcoma

The exact cause of soft tissue sarcoma remains unknown in most cases, but researchers have identified several factors that may increase the risk of developing this rare cancer:

Genetic Factors

• Inherited syndromes: Certain genetic conditions significantly increase sarcoma risk, including Li-Fraumeni syndrome, neurofibromatosis type 1, familial adenomatous polyposis (FAP), and retinoblastoma
• Family history: Having close relatives with sarcoma may slightly increase risk
• Genetic mutations: Specific gene changes that can be inherited or acquired

Previous Radiation Exposure

• Radiation therapy: Previous radiation treatment for other cancers can increase sarcoma risk in the treated area, typically developing 5-10 years or more after exposure
• High-dose exposure: The risk increases with higher radiation doses

Chemical Exposure

• Vinyl chloride: Used in plastics manufacturing
• Arsenic: Long-term exposure through contaminated water or occupational settings
• Herbicides: Particularly those containing phenoxyacetic acids
• Dioxin: Industrial chemical exposure

Lymphedema

• Chronic swelling of the arms or legs due to lymphatic system damage, whether from surgery, radiation, infection, or other causes
• The condition called lymphangiosarcoma can develop in chronically swollen limbs

Viral Infections

• Human herpesvirus 8 (HHV-8): Associated with Kaposi sarcoma, particularly in immunocompromised individuals
• HIV/AIDS: Weakened immune system increases susceptibility

Other Risk Factors

• Age: Risk increases with age, though sarcomas can occur at any age
• Previous injury: While trauma doesn’t cause sarcoma, injuries may draw attention to a pre-existing tumor

It’s important to emphasize that having one or more risk factors doesn’t mean someone will definitely develop soft tissue sarcoma. Many people with risk factors never develop the disease, while many patients have no identifiable risk factors at all.

Prevention Strategies

Because the exact causes of most soft tissue sarcomas are unknown, there’s no guaranteed way to prevent this disease. However, certain strategies may help reduce risk:

Minimize Environmental Exposures

• Use protective equipment when working with chemicals, especially vinyl chloride, arsenic, and herbicides
• Follow workplace safety guidelines for handling hazardous materials
• Avoid unnecessary exposure to high doses of radiation
• Be aware of arsenic levels in drinking water and take appropriate measures if contamination is present

Genetic Counseling

• If you have a family history of sarcoma or known genetic syndromes, consider genetic counseling
• Genetic testing may help identify inherited conditions that increase risk
• Increased surveillance may be recommended for high-risk individuals

Manage Lymphedema

• If you have chronic lymphedema, work with healthcare providers to manage it properly
• Use compression garments as recommended
• Maintain good skin care to prevent infections
• Engage in appropriate exercise as directed by your healthcare team

Regular Health Monitoring

• Perform regular self-examinations to check for unusual lumps or masses
• Report any persistent or growing lumps to your healthcare provider promptly
• Attend regular check-ups, especially if you have risk factors
• Don’t ignore symptoms that persist or worsen over time

Healthy Lifestyle

• Maintain a balanced diet rich in fruits, vegetables, and whole grains
• Exercise regularly to support overall health
• Avoid tobacco products, which increase risk for many cancers
• Limit alcohol consumption

While these strategies may help reduce risk or catch sarcomas early, remember that most soft tissue sarcomas cannot be prevented. The most important thing is awareness—knowing the signs and symptoms and seeking medical attention promptly for any concerning changes in your body.

Frequently Asked Questions

How fast do soft tissue sarcomas grow?

Growth rates vary significantly depending on the type and grade of sarcoma. Low-grade sarcomas typically grow slowly over months or even years, while high-grade sarcomas can grow more rapidly over weeks to months. Any lump that grows noticeably over time should be evaluated by a healthcare provider.

Are soft tissue sarcomas always cancerous?

Yes, by definition, sarcomas are malignant (cancerous) tumors. However, most soft tissue lumps are not sarcomas—they’re benign growths like lipomas (fatty tumors), cysts, or fibromas. Only a medical professional can determine whether a lump is cancerous through examination and appropriate testing.

Can soft tissue sarcoma be felt under the skin?

Yes, many soft tissue sarcomas can be felt as a lump or mass under the skin, especially those located in the arms, legs, or trunk. However, deep-seated sarcomas, particularly those in the abdomen or retroperitoneum, may not be palpable until they’ve grown quite large.

What’s the difference between soft tissue sarcoma and other cancers?

Soft tissue sarcomas develop from mesenchymal tissues (connective tissues like muscle, fat, blood vessels, and nerves), while most other cancers are carcinomas that develop from epithelial tissues (tissues that line organs and glands). Sarcomas are much rarer, accounting for less than 1% of adult cancers.

Do soft tissue sarcomas spread to other parts of the body?

Yes, soft tissue sarcomas can metastasize (spread) to other parts of the body, most commonly to the lungs. High-grade sarcomas are more likely to spread than low-grade ones. Early detection and treatment are important to reduce the risk of metastasis.

Should I be worried about every lump I find?

Most lumps are benign and not cause for alarm. However, you should have a lump evaluated by a healthcare provider if it: persists for more than 2 weeks, continues to grow, is larger than 2 inches (5 cm), is painful, is deep-seated or fixed in place, or returns after being removed.

At what age do soft tissue sarcomas typically occur?

Soft tissue sarcomas can occur at any age, including in children, but they become more common with advancing age. The median age at diagnosis is around 60 years old. However, certain types of sarcomas are more common in specific age groups.

Can exercise or physical activity cause soft tissue sarcoma?

No, physical activity and exercise do not cause soft tissue sarcoma. While trauma or injury might draw attention to a lump that was previously unnoticed, the injury itself doesn’t cause the cancer to develop.

How is soft tissue sarcoma diagnosed?

Diagnosis typically involves physical examination, imaging studies (such as MRI, CT scans, or ultrasound), and biopsy. A biopsy, where a sample of tissue is removed and examined under a microscope, is necessary to confirm the diagnosis and determine the specific type of sarcoma.

What should I do if I notice symptoms of soft tissue sarcoma?

If you notice a persistent or growing lump, pain, or any of the symptoms described in this article, schedule an appointment with your healthcare provider. While most lumps are not cancerous, early evaluation is important. Don’t wait to see if symptoms resolve on their own if a lump continues to grow or persists beyond a few weeks.

References:

• American Cancer Society – Soft Tissue Sarcoma
• Mayo Clinic – Soft Tissue Sarcoma
• National Cancer Institute – Soft Tissue Sarcoma
• NHS – Soft Tissue Sarcoma
• MD Anderson Cancer Center – Sarcoma