Dedifferentiated Liposarcoma

Dedifferentiated Liposarcoma is a malignant (cancerous), soft-tissue sarcoma that most commonly occurs in the retroperitoneum, or the area in the back of the abdomen. It is an atypical liposarcoma that can arise from a low-grade, well-differentiated liposarcoma that can progress overtime into a dedifferentiated liposarcoma. Treatment includes surgical resection or removal of the tumor.

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What is Dedifferentiated Liposarcoma?

Dedifferentiated liposarcoma is the least common subtype of liposarcoma and usually arises from a well-differentiated liposarcoma.  Progression occurs in 17 % of patients when well-differentiated liposarcoma is located in the retroperitoneum and 6% of cases when well-differentiated liposarcoma is located in the extremities. Dedifferentiated liposarcoma has also been defined as an atypical liposarcoma that progresses or changes over the course of time with variable histologic grade. This is essentially a low grade liposarcoma mixed with a high grade spindle cell sarcoma.  These tumors occur mostly in adults and tend to grow more aggressively than a low grade well-differentiated liposarcoma.  They arise most commonly in the retroperitoneum.

Who is usually affected?
Who is usually affected?
  • • The majority of cases occurs in individuals over the age of 50.
  • • There is no gender predilection.
  • • Accounts for about 18% of all liposarcomas.
  • • Can progresses from well-differentiated liposarcomas (WDLPS) and their presentation is more frequent after a recurrence of WDLPS- Up to 17% of untreated, well-differentiated liposarcomas progresses to DDLPS.
Common Sites Involved
Common Sites Involved
  • • Retroperitoneum
  • • Lower extremities
  • • Upper extremities
  • • Trunk
  • • Can metastasize to lungs, liver, lymph nodes and other bones.


Signs and Symptoms
Signs and Symptoms
  • • Signs and symptoms include pain and swelling. 
  • • Most patients present with an enlarging mass that can grow to a fairly large size.


  • • Aside from the uncontrollable growth of abnormal cells to create a fatty mass, there is no known cause.
  • • Can progress into dedifferentiated liposarcomas from well-differentiated liposarcomas.
Biological Behavior
Biological Behavior
  • • Up to 17% of WDLPS progress to DDLPS.
  • • DDLPS has 54-64% of overall survival and has 66 to 89% of disease-specific survival.
  • • Progression to DDLPS occurs in 17% of the retroperitoneal WDLPS and 6% for the WDLPS in the extremities.
  • • Location and mitotic count are the most important prognosis factors.
  • • The work-up for dedifferentiated liposarcoma often consists of a physical examination, X-ray, MRI, CT, and bone scans. Also, a bone scan, CT PET scan, and CT chest/abdomen/pelvis may be ordered to check if the tumor has spread, or metastasized, to the chest/abdomen/ pelvis or other parts of the body. The diagnosis is often confirmed with a biopsy, which samples the tumor for further analysis.

Risk to your limbs

Dedifferentiated liposarcoma is a malignant sarcoma that commonly occurs in the retroperitoneum, or the area in the back of the abdomen. Like all soft-tissue sarcomas, these liposarcomas grow in the soft-tissues of the extremities and compromise or destroy the affected soft-tissue and muscles. These tumors can compress or stretch important vessels and nerves, and occasionally wrap around these structures making it difficult to remove the mass without an amputation. They also have the potential to invade adjacent bones. Without treatment, dedifferentiated liposarcomas can metastasize or spread throughout the body, with the lungs, liver, and bones being the most common sites. Several risk factors include location and size of the sarcoma, and mitotic count.

Radiographic imaging is used to help form a diagnosis. These include X-Ray, MRI, CT and Bone Scans

An example of an MRI is shown.

Treatment of Dedifferentiated Liposarcoma

The treatment of dedifferentiated liposarcoma includes surgical excision through wide or radical resections. Limb-sparing surgery is performed whenever possible, however if the tumor compresses, stretches, or is wrapped around vital nerves and vessels then an amputation may be performed. Additionally, radiation and/or chemotherapy is recommended as adjuvant treatment. Early diagnosis and treatment is beneficial, as there is a 15%-20% chance of metastasis without early and effective treatment.

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Myself and my amazing team are dedicated to saving your life and your limb. Losing a limb because of a tumor can be a terrifying experience. But, it does not have to be the only option. I’ve spent 20+ years as a Board-Certified Orthopedic Surgeon and Orthopedic Oncologist.

I’ve devoted my career to helping children and adults afflicted with bone and soft tissue masses by performing complex limb saving surgeries. Most patients can have their limb saved, which may require innovative techniques.

Patients afflicted with musculoskeletal tumors have complex conditions that are best taken care of at large hospitals. I am the Chairman of Orthopedics and Chief of Orthopedic Oncology at Morristown Medical Center. My philosophy is a multidisciplinary team approach, working together to tailor treatment to individual patients. Education and research are essential to my practice, providing the best setting for extraordinary patient care. Because of this, we have some of the top results in the country.