Liposarcoma is a rare type of cancer that affects the fat cells in deep soft tissue, such as in the thigh or retroperitoneum.

The tumors are usually very soft and fleshy, but can sometimes be firmer in texture. Smaller “satellite” tumors may extend beyond the primary mass. Sarcomas affect approximately 5,000 people annually.

There are four existing subtypes of liposarcomas:

• Well-differentiated liposarcoma: Applies to tumors that develop in the retroperitoneum
• Dedifferentiated liposarcoma: Applies to well-differentiated liposarcomas adjacent to a less differentiated tumor
• Myxoid/round cell liposarcoma
• Pleomorphic liposarcoma

Signs & Symptoms

A patient will likely notice the large mass in the soft tissue. The condition does not usually show any symptoms until the tumor becomes quite large or painful. If the tumor is in the retroperitoneum, the patient may experience weight loss and pain in the abdomen. They can also cause kidney failure due to the tumor putting pressure on the kidneys or ureter.

Diagnosis & Treatment

The first step to diagnosing liposarcoma is to have a physical exam done by a physician. Depending on those results, the doctor may order additional tests, usually a scan such as an MRI (magnetic resonance imaging), x-ray, or CT/CAT scan.

These exams would identify any masses in the body; an MRI could provide a detailed image of the mass, which would help the doctor determine the stage and severity of the mass. Liposarcomas are very distinct, and further testing (such as a biopsy, in which a small piece of the tissue is cut away from the mass and examined under a microscope) may not be needed.

Liposarcomas are usually treated with surgery—the goal being to remove the entire mass and prevent it from recurring.

In the past, many patients faced limb amputation as one of the only ways to ensure the tumor would not return; due to advances in surgery and a better understanding of how sarcomas function, many patients can simply have the tumor removed and preserve their limb.

However, even amputation may not guarantee that the tumor will not return. Radiation is often used in conjunction with surgery to decrease the patient’s odds of a recurrence.

Prognosis

A patient’s prognosis depends on the size, location (particularly in relation to any lymph nodes) and stage of the mass. The 5-year survival rate of a high metastatic tumor is approximately 40 percent.