Liposarcoma
Liposarcoma is a cancer that arises from fat — but it is not the same as the harmless lipomas almost everyone has heard of. There are several types, each with its own behaviour and its own treatment. Most are very treatable, and many are curable, especially when looked after by a team that sees them often.
What liposarcoma is — in plain words
Fat is not just padding. It is a living tissue with cells, blood vessels, and the ability — very rarely — for its cells to turn cancerous. When that happens, the result is a liposarcoma. Because fat is everywhere in the body, liposarcoma can theoretically arise anywhere; in practice, the two commonest sites by far are the back of the abdomen (the retroperitoneum) and the thigh.
A liposarcoma is not a lipoma. Lipomas are benign, soft, mobile lumps that millions of people carry without trouble. Liposarcomas are firmer, deeper, larger, and they grow. The distinction matters, but the way to settle it is not to argue about a lump in the clinic — it is to image it and, when in doubt, to biopsy it properly.
Liposarcoma belongs to the family of soft-tissue sarcomas, and the same rule applies: it is best looked after by a sarcoma team from the very first decision.
The four subtypes — they behave very differently
Pathologists divide liposarcoma into four main subtypes. The differences are not academic — they decide the surgery, the radiation, the chemotherapy, and the outlook.
Well-differentiated liposarcoma
The most common subtype. Looks almost like normal fat under the microscope and grows slowly. Most often appears in the retroperitoneum, where it can reach a remarkable size before being discovered. Rarely spreads — but tends to come back locally if surgery is incomplete.
Dedifferentiated liposarcoma
A more aggressive cancer that arises from a well-differentiated tumour — either alongside it from the start, or years later in a recurrence. Looks far more abnormal under the microscope and is capable of spreading to the lungs or liver.
Myxoid liposarcoma
The classic liposarcoma of younger adults, typically in the thigh. Has a distinctive jelly-like appearance. Notably sensitive to radiation, and one of the more chemosensitive sarcomas. Can spread to unusual sites — other soft tissues and bones, not only the lungs — so staging is a little different.
Pleomorphic liposarcoma
The rarest and the most aggressive of the four. High-grade by definition, with a real risk of spread. Treated like other high-grade soft-tissue sarcomas — surgery, radiation, and often chemotherapy.
Who tends to get liposarcoma — and where
Liposarcoma is rare. Most subtypes affect adults in middle age and beyond — fifties to seventies — with myxoid liposarcoma being the exception, often appearing in people in their twenties to forties. Men and women are affected roughly equally. There is no strong known cause for most cases; previous radiation to the area is one recognised risk factor.
By location:
- The retroperitoneum — the space behind the abdominal contents, around the kidneys and great blood vessels — is the commonest site for well-differentiated and dedifferentiated liposarcoma. Because the space is large and "silent", tumours here often grow to many kilograms before causing any noticeable symptom.
- The thigh is the commonest extremity site. Myxoid liposarcoma in particular favours the deep tissues of the thigh.
- Other sites — chest wall, abdominal wall, head and neck — are less common but well recognised.
Signs and symptoms to take seriously
A painless, deep, growing lump
Especially in the thigh. Larger than 5 cm, deeper than a normal "skin" lump, and slowly enlarging over weeks or months.
A vague abdominal mass or fullness
A retroperitoneal liposarcoma may simply produce a feeling of being full, a visible swelling, or back pain. Sometimes the first sign is a tumour seen on a scan done for something else.
Pressure symptoms
Large retroperitoneal tumours can press on the bowel (constipation), the bladder (urinary frequency), the ureter (kidney swelling on a scan), or the leg veins (leg swelling on one side).
A lump returning at the site of a previous "lipoma"
If a lump removed as a lipoma comes back, do not assume it is the same thing. It deserves a careful look — sometimes what was called a lipoma was actually a well-differentiated liposarcoma all along.
"When a retroperitoneal liposarcoma is found, it has almost always been growing quietly for years. That sounds frightening, but it also means there is usually time — time to scan properly, time to plan the surgery carefully, time to do this once and do it right."
How liposarcoma is diagnosed
The workup is the same disciplined sequence used for any soft-tissue sarcoma.
- MRI of the primary site — for limb tumours, MRI shows the relationship between the tumour and the muscles, nerves, and vessels around it. For retroperitoneal tumours, a high-quality CT of the abdomen and pelvis is usually the main scan, often supplemented by MRI.
- CT scan of the chest — the lungs are the main site of spread for the more aggressive subtypes; CT chest is part of staging for almost every patient.
- Image-guided core-needle biopsy — planned along a path that the surgeon will later remove. For retroperitoneal tumours, this is usually done through the back rather than across the abdomen, to avoid seeding tumour into the peritoneal cavity.
- Specialist sarcoma pathology — the difference between a lipoma, a well-differentiated liposarcoma, and a dedifferentiated liposarcoma can be subtle. A pathologist experienced in sarcoma should review the slides.
- Molecular testing — well-differentiated and dedifferentiated liposarcomas almost always carry an amplification of a gene called MDM2. Testing for MDM2 amplification can settle a difficult diagnosis and is part of the modern workup. Myxoid liposarcoma has its own signature — a fusion of the FUS and DDIT3 genes.
How we treat liposarcoma
Treatment is decided by a multidisciplinary team — a sarcoma surgeon, a medical oncologist, a radiation oncologist, a pathologist, and a radiologist all reviewing the case together. The plan depends on the subtype, the grade, the size, and the location.
Surgery — the central treatment
For nearly every localised liposarcoma, surgery is the main treatment. The goal is complete removal with a margin of normal tissue around the tumour.
- Limb liposarcomas are almost always removed with a limb-sparing operation — the muscle compartment containing the tumour, or the involved part of it, taken out together with the tumour.
- Retroperitoneal liposarcomas often require a much larger operation, sometimes including a kidney, part of the bowel, or part of the abdominal wall, depending on which organs the tumour is wrapped around. These operations should only be done in specialist centres.
Radiation therapy
Radiation is added to surgery in many cases — particularly for high-grade tumours and for myxoid liposarcoma, which is unusually sensitive to it. It can be given before surgery (smaller field, lower dose) or after surgery (larger field, higher dose). For low-grade well-differentiated tumours that can be cleanly removed, radiation may not be needed at all.
Chemotherapy
The role of chemotherapy in liposarcoma is smaller than in some other sarcomas, and varies by subtype:
- Myxoid liposarcoma is the most chemosensitive subtype — doxorubicin-based chemotherapy can produce real shrinkage and is often used for large or high-grade cases.
- Dedifferentiated and pleomorphic liposarcomas are sometimes treated with chemotherapy, particularly when the tumour is large or has spread.
- Well-differentiated liposarcoma usually does not respond to chemotherapy — surgery is the answer, and chemotherapy is rarely used.
Read more about chemotherapy →
Targeted therapy for advanced disease
For liposarcomas that have spread or come back after surgery, several systemic options exist beyond classical chemotherapy — trabectedin (particularly effective in myxoid liposarcoma), eribulin, and a number of drugs in clinical trials. Drugs that target MDM2 are an active area of research for well-differentiated and dedifferentiated liposarcoma and may become available in the next few years.
What the outlook honestly looks like
The outlook depends overwhelmingly on the subtype, the grade, the size, the location, and whether surgery achieved clear margins.
- Well-differentiated liposarcoma, completely removed, has an excellent long-term outlook. Local recurrence is the main worry, especially for retroperitoneal cases — so follow-up is long.
- Myxoid liposarcoma of the limb, treated with proper surgery and radiation, has a five-year survival typically in the 70–90% range.
- Dedifferentiated liposarcoma is more difficult — five-year survival is around 40–60%, better when surgery is complete.
- Pleomorphic liposarcoma, the rarest, has the most aggressive behaviour, with five-year survival around 30–50%.
Even when liposarcoma comes back or spreads, it is often a slowly progressive disease — one that can be controlled with further surgery, radiation, and systemic treatment for years.
Life during and after treatment
For a limb liposarcoma, the most demanding part of treatment is usually the surgery and the weeks of physiotherapy that follow. Most people regain very good function. For a retroperitoneal liposarcoma, recovery from the operation takes longer — typically several weeks to a few months — but most patients return to ordinary life. Radiation is usually well tolerated, with skin reactions and fatigue that settle within weeks. Chemotherapy, when used, is the most intense period and the one when family support, gentle nutrition, and a steady routine matter most.
Through all of it — work where possible, prayer, time with family, simple food, light exercise — ordinary life is part of the treatment, not separate from it.
After treatment — long-term follow-up
Liposarcomas, especially in the retroperitoneum, can come back many years after the original surgery. Follow-up therefore continues for a long time:
- Clinical review and a scan of the primary site every 3–6 months for the first 2–3 years, then less often.
- CT scan of the chest every 6–12 months — more often for high-grade tumours.
- For retroperitoneal cases, CT or MRI of the abdomen continues at intervals for at least 10 years.
Read about survivorship care →
The most important things to take away
- A growing, deep lump — especially in the thigh or the abdomen — deserves an MRI or CT, not a quick excision.
- The first operation is the one that matters most. It should be done by a surgeon and a team experienced in sarcoma.
- Subtype changes everything — well-differentiated, dedifferentiated, myxoid and pleomorphic liposarcoma are really four different diseases.
- Follow-up is long. Liposarcoma can return years later, but if it does, it is often still treatable.
Just been told it might be liposarcoma? Bring your scans.
We will look at the imaging and the pathology together, explain exactly which subtype is being considered, and help you get to the right surgical team for the next step. No rush, no jargon.
Medically reviewed by
Dr. Rehan Abdullah
Dr. Rehan Abdullah is a dual-trained clinical and radiation oncologist with over a decade of experience treating both solid tumours and hematologic malignancies. He serves as Consultant Oncologist at INMOL Hospital and sees patients at Farooq Hospital and Healthnox Medical Center, Lahore. Read full profile →
This page is patient education, not a substitute for an in-person consultation. Cancer care must be individualised. Read our medical disclaimer →