Overview
Well-differentiated liposarcoma (WDLPS), also known as atypical lipomatous tumor (ALT), is the most common subtype of liposarcoma, a malignant tumor arising from fat (adipose) tissue. It is classified as a low-grade soft tissue sarcoma and typically presents as a slow-growing, painless mass. The tumor most commonly occurs in the retroperitoneum (the space behind the abdominal cavity), the limbs (particularly the thigh), the mediastinum, and the spermatic cord. Well-differentiated liposarcoma is characterized by the presence of supernumerary ring or giant marker chromosomes containing amplified segments of chromosome 12q13-15, which includes the MDM2 and CDK4 oncogenes. MDM2 amplification is a hallmark molecular feature used in diagnosis. Clinically, patients often present with a large, deep-seated mass that may cause symptoms related to compression of adjacent structures, particularly when located in the retroperitoneum, where tumors can grow to considerable size before detection. Symptoms may include abdominal fullness, pain, early satiety, or organ dysfunction depending on the location and size of the tumor. When located in the extremities, the tumor is often termed atypical lipomatous tumor and generally carries an excellent prognosis with complete surgical excision. However, retroperitoneal well-differentiated liposarcomas have a higher risk of local recurrence and may undergo dedifferentiation into a higher-grade sarcoma (dedifferentiated liposarcoma), which carries a significantly worse prognosis. The primary treatment for well-differentiated liposarcoma is complete surgical resection with wide margins. Radiation therapy may be considered as an adjunct, particularly for retroperitoneal tumors, to reduce local recurrence risk. Conventional chemotherapy has limited efficacy in this subtype. Targeted therapies directed against MDM2 and CDK4 are under active investigation in clinical trials. Long-term follow-up with imaging surveillance is essential due to the risk of local recurrence and potential dedifferentiation. The disease predominantly affects adults, with a peak incidence between the fifth and seventh decades of life.
Also known as:
Clinical phenotype terms— hover any for plain English:
Sporadic
Usually appears on its own, not inherited from a parent
Adult
Begins in adulthood (age 18 or older)
FDA & Trial Timeline
10 eventsSouthern California Institute for Research and Education — PHASE2
Assiut University
Universiti Sains Malaysia — NA
University Hospital, Antwerp
Memorial Sloan Kettering Cancer Center — PHASE1, PHASE2
McGill University Health Centre/Research Institute of the McGill University Health Centre — NA
Nermeen Gamil Ahmed
Shanghai Pharmaceuticals Holding Co., Ltd — PHASE1, PHASE2
Edwards Lifesciences — NA
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Well-differentiated liposarcoma.
2 clinical trialsare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Well-differentiated liposarcoma.
Community
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Start the conversation →Latest news about Well-differentiated liposarcoma
Disease timeline:
New recruiting trial: Postoperative Analgesia Intervention With Non-opioid Alternatives (PAIN-Alt) Trial - Breast Surgery
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: LGG Supplementation in Patients With AUD and ALD
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: A Prospective, Randomized, Open Label Trial of Two Doses of Oral Betaine
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: Nottingham Community Liver Biomarkers Cohort
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: TAF (Tenofovir Alafenamide) for Preventing Progression of Liver Disease in Non-cirrhotic Chronic HBV Infection With Normal ALT and Low Viral Load.
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: Nucleoside (Acid) Analogues Treatment in Patients With Normal ALT and Positive HBVDNA.
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: A Study to Evaluate Impact of Efanesoctocog Alfa on Long-term Joint Health in Participants With Hemophilia A in Taiwan
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: Anterolateral Tigh (ALT) Flaps Oxygenation Monitoring by NIRS
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: Identification of a New Blood Biomarker for the Diagnosis and Prognosis of Liposarcomas
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
New recruiting trial: Measuring if Immunotherapy Plus Chemotherapy is Better Than Chemotherapy Alone for Patients With Aggressive Poorly Differentiated Sarcomas
A new clinical trial is recruiting patients for Well-differentiated liposarcoma
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Common questions about Well-differentiated liposarcoma
What is Well-differentiated liposarcoma?
Well-differentiated liposarcoma (WDLPS), also known as atypical lipomatous tumor (ALT), is the most common subtype of liposarcoma, a malignant tumor arising from fat (adipose) tissue. It is classified as a low-grade soft tissue sarcoma and typically presents as a slow-growing, painless mass. The tumor most commonly occurs in the retroperitoneum (the space behind the abdominal cavity), the limbs (particularly the thigh), the mediastinum, and the spermatic cord. Well-differentiated liposarcoma is characterized by the presence of supernumerary ring or giant marker chromosomes containing amplified
How is Well-differentiated liposarcoma inherited?
Well-differentiated liposarcoma follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Well-differentiated liposarcoma typically begin?
Typical onset of Well-differentiated liposarcoma is adult. Age of onset can vary across affected individuals.
Are there clinical trials for Well-differentiated liposarcoma?
Yes — 2 recruiting clinical trials are currently listed for Well-differentiated liposarcoma on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Well-differentiated liposarcoma?
3 specialists and care centers treating Well-differentiated liposarcoma are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.