What are the other Names for this Condition? (Also known as/Synonyms)

• Myxoid LS
• Round Cell Liposarcoma

What is Myxoid Liposarcoma? (Definition/Background Information)

• Myxoid Liposarcomas are slow-growing, malignant soft tissue tumors. These tumors are typically present on the limbs. The occurrence of these tumors in the retroperitoneal space is rare
• The cause of development of these tumors is unknown, but some genetic mutations have been observed
• The treatment involves a complete surgical excision and removal of the tumor. However, Myxoid Liposarcomas can metastasize to the bone and soft tissues in the body, and they have a tendency to recur
• The prognosis depends upon several factors including the tumor location and morphological pattern (as diagnosed by a pathologist)
• A liposarcoma (LPS or LS) is a rare and malignant tumor of the fat cells. They are generally asymptomatic and can occur anywhere in the body
• There are 4 main types of liposarcomas and these include:
  • Well-Differentiated Liposarcoma (WDLS): Approximately 45% of all types of liposarcomas are well-differentiated
  • Dedifferentiated Liposarcoma: It is a high-grade morphology tumor         
  • Myxoid Liposarcoma: This type constitute 30% of all liposarcomas
  • Pleomorphic Liposarcoma (PLS): It is the rarest type and constitute about 5% of all liposarcomas

Who gets Myxoid Liposarcoma? (Age and Sex Distribution)

• Myxoid Liposarcoma is observed in both men and women, typically in the 30-50 years age group
• There is no known ethnic or racial preference; it is observed worldwide

What are the Risk Factors for Myxoid Liposarcoma? (Predisposing Factors)

• No clear risk factors have been identified for Myxoid Liposarcoma occurrence

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Myxoid Liposarcoma? (Etiology)

• The exact cause and mechanism of formation of Myxoid Liposarcoma is unknown
• It is thought to occur spontaneously due to certain genetic mutations (chromosomal abnormalities)
• Contrary to some beliefs, trauma does not contribute to the formation of liposarcomas. Current studies also do not support that liposarcomas arise from lipomas (very common, benign fatty tumors)

What are the Signs and Symptoms of Myxoid Liposarcoma?

The signs and symptoms of Myxoid Liposarcomas are mostly dependent upon the location of the tumors. The indications may include:

• The tumors are slow-growing and painless. They are also multifocal (can occur in more than one area)
• Myxoid Liposarcoma is frequently found on the limbs (arms and legs) and rarely in the abdominal region (retroperitoneum)
• If the tumor occurs on the thigh, a painless lump may be observed. Thigh tumors may also cause leg pain and restricted movement (walking difficulties)
• If it forms in the retroperitoneal space, the tumor may not cause any symptoms for a long period of time, until it grows to a large size and compresses the adjacent organs in the abdomen. This is one of the reasons why retroperitoneal tumors remain undetected during their early development stage

How is Myxoid Liposarcoma Diagnosed?

Myxoid Liposarcoma may be diagnosed by using the following tools and procedures:

• Physical examination, evaluation of patient’s medical history
• Radiological studies, such as x-ray, whole body CT scan, MRI, or ultrasound scan of the affected region
• Needle biopsy of tumor
• Open biopsy of tumor: A tissue biopsy is performed and sent to a laboratory for a pathological examination, who examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Note: A needle biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a needle biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred.

Myxoid Liposarcoma has two morphological patterns - myxoid pattern and round cell pattern, when examined under a microscope by a pathologist. This pattern has a bearing on the prognosis of the condition.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Myxoid Liposarcoma?

Complications from Myxoid Liposarcomas may include the following:

• Large tumors in the retroperitoneal cavity can lead to weight loss, abdominal pain, frequent urination, and kidney failure due to compression of the kidney
• Tumors in the leg may result in the formation of varicose veins
• Metastasis of the tumor to other body regions, such as to the bone and soft tissues
• Damage to the muscles, vital nerves, and blood vessels, during surgery to remove Myxoid Liposarcoma
• The condition has the tendency to recur after treatment (incomplete surgical removal of the tumor)

How is Myxoid Liposarcoma Treated?

Treatment measures for Myxoid Liposarcoma include the following:

• Complete surgical excision of the tumor with clear margins
• Radiation therapy and chemotherapy are employed depending upon the specific case
• Also, in some rare cases, limb amputation may have to be undertaken, in case of limb tumors
• Post-operative care is important: One must maintain minimum activity levels, until the surgical wound heals
• Follow-up care with regular screening and check-ups are important, since the tumor may recur in many cases

How can Myxoid Liposarcoma be Prevented?

Current medical research has not established a way of preventing Myxoid Liposarcomas.

What is the Prognosis of Myxoid Liposarcoma? (Outcomes/Resolutions)

• The prognosis of Myxoid Liposarcoma is good with early detection and surgical intervention. Tumors that can be completely excised have better prognosis than those that cannot be completely removed
• Nevertheless, the outcome is dependent upon the site of the tumor and pattern of the tumor, when examined by a pathologist under the microscope. If majority of the tumor is myxoid pattern, then the overall survival is 90% at 5 years. if the predominant pattern is round cell, then the overall survival is 40%
• Generally, the mortality rate is high, if the tumor is present in the retroperitoneal region

Additional and Relevant Useful Information for Myxoid Liposarcoma:

In general, liposarcomas form approximately 5% of all sarcomas.