Quick answer. Sarcoma is a rare group of cancers that start in the connective tissues of the body, such as muscle, fat, nerves, blood vessels and bone. The single most useful thing to know is that any deep lump that is growing, especially one larger than about 5cm, should be checked by a doctor rather than watched.
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Sarcoma is an uncommon cancer in Singapore, but because it can grow quietly in places where lumps are easy to dismiss, awareness matters. Unlike the more familiar cancers of the breast, lung or bowel, sarcoma arises from the body’s connective tissue and is broadly split into soft tissue sarcoma (muscle, fat, nerves, blood vessels) and bone sarcoma (such as osteosarcoma). Most lumps people find are harmless, but sarcoma is the reason a doctor will sometimes want to image or biopsy a deep, enlarging mass rather than simply reassure you.
This guide explains what sarcoma is, the symptoms to watch for, how it is diagnosed and the main treatment options used in Singapore. It is written to inform, not to alarm. Many lumps turn out to be benign, and when sarcoma is found and treated, outcomes are best when it is caught early, which is exactly why prompt assessment of a suspicious lump is worth it.
At a glance
| Feature | More reassuring (often benign) | Warrants prompt review |
|---|---|---|
| Size | Small and stable, often under 5cm | Larger than about 5cm or still growing |
| Depth | Just under the skin, soft and mobile | Deep to the muscle, feels fixed |
| Change over time | Unchanged for months or years | Enlarging over weeks to months |
| Texture | Soft and squishy (e.g. a lipoma) | Firm or hard, not easily moved |
| Symptoms | Painless and not bothersome | New pain, or a previously removed lump returning |
What is sarcoma?
Sarcoma is a cancer that begins in the body’s connective and supporting tissues rather than in an organ lining. There are two broad families. Soft tissue sarcoma can develop in fat, muscle, nerves, tendons or blood vessels, anywhere in the body but commonly in the limbs or abdomen. Bone sarcoma, such as osteosarcoma and Ewing sarcoma, starts in the bone itself.
Sarcomas are rare and make up a small fraction of all cancers. Some types are more common in children and young adults (particularly certain bone sarcomas), while others tend to appear in older adults. Because they are uncommon and can look like an ordinary lump or muscle ache, sarcomas are sometimes diagnosed later than other cancers, which is why a low threshold for checking a deep or growing lump is sensible.
Symptoms & signs
Sarcoma symptoms depend on where the tumour is and how large it has grown. Many cause few problems until they reach a noticeable size. Common signs include:
- A lump that is growing, especially one deep in a limb or the trunk and larger than about 5cm
- A lump that feels firm and fixed rather than soft and freely mobile
- Persistent bone pain that may be worse at night or not clearly linked to an injury
- Swelling over a bone, sometimes with reduced movement in a nearby joint
- Abdominal swelling, fullness or discomfort if a sarcoma grows inside the abdomen
- A lump that returns after a previous one was removed
Pain is not a reliable guide. A painless lump can still be a sarcoma, so size and growth matter more than whether it hurts.
Causes & risk factors
For most people, no clear cause is ever found, and nothing they did caused the sarcoma. However, some factors are associated with a higher risk:
- Previous radiotherapy to the area, usually many years earlier for another cancer
- Certain inherited genetic conditions, such as Li-Fraumeni syndrome, neurofibromatosis type 1 or retinoblastoma
- Long-standing lymphoedema (chronic swelling of a limb)
- Exposure to some industrial chemicals, in a small number of soft tissue sarcomas
It is important to know that everyday knocks, bruises and old injuries do not cause sarcoma. An injury sometimes simply draws attention to a lump that was already there.
How sarcoma is diagnosed
Diagnosis usually begins with a clinical examination, then proceeds in a careful sequence so the lump is not disturbed before it is understood:
- Imaging: ultrasound is often first, followed by MRI to map a soft tissue lump, or X-ray and MRI for a suspected bone tumour.
- Biopsy: a sample of the lump is taken (commonly a core-needle biopsy, sometimes image-guided) and examined under the microscope. The biopsy is planned by the treating team so it does not complicate later surgery.
- Staging scans: a CT scan of the chest and sometimes a PET scan check whether the cancer has spread, since lungs are a common site for sarcoma to spread to.
Because sarcomas are rare, they are best assessed by a team experienced in them, who together plan diagnosis and treatment.
Treatment options
Treatment is tailored to the type, size, location and grade of the sarcoma, and is usually planned by a multidisciplinary team. The main options are:
- Surgery: the mainstay for most localised sarcomas, aiming to remove the tumour completely with a margin of healthy tissue. Limb-sparing surgery is the goal wherever possible.
- Radiotherapy: often given before or after surgery to reduce the chance of the cancer coming back in the same area.
- Chemotherapy: used for certain sarcoma types (more commonly in some bone sarcomas and in children) and where there is a risk of, or actual, spread.
- Targeted therapy and clinical trials: some sarcoma subtypes respond to specific drug therapies, and trials may be discussed in specialist centres.
Many people with localised sarcoma are treated with the aim of cure. Outcomes vary widely by type and stage, so your specialist is the right person to explain what to expect in your situation. We do not publish survival figures here because they depend heavily on the individual case.
When to see a doctor & which specialist
See a doctor promptly if you notice any of these warning signs, even if the lump does not hurt:
- A lump anywhere on the body that is larger than about 5cm
- A lump that is growing, deep-seated, or feels firm and fixed
- A lump that has come back after being removed before
- Persistent, unexplained bone pain, especially at night
These signs do not mean you have cancer, but they do mean it should be assessed without delay. Your GP can examine the lump and arrange the first scan. If a sarcoma is suspected or confirmed, care is led by a cancer specialist. You can find a relevant specialist through the best oncologists in Singapore directory. Sarcoma is rare and very different from common benign lumps such as a lipoma, which is soft, mobile and harmless; when in doubt, getting it checked is the safest path.
Related guides
- Best Oncology Clinics in Singapore — our editorial shortlist
- oncology clinics directory
- Croup
- Bronchiolitis
- Stomach cancer
- Pancreatic cancer
- Peptic ulcer
Sources
- NHS – Soft tissue sarcomas
- NHS – Bone cancer
- Mayo Clinic – Sarcoma
- SingHealth – Sarcoma
- HealthHub Singapore – Cancer
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