dedifferentiated liposarcoma

A poorly-differentiated pleomorphic sarcoma which accounts for 10% of liposarcomas. It is a mixture of well-differentiated liposarcoma and a high-grade non-lipogenic sarcoma, an aggressive component. About 50% of retroperitoneal liposarcomas are dedifferentiated. 75% occur in the retroperitoneum; other sites include the extremities and paratesticular region. Dedifferentiated areas can be that of:
(1) High-grade pleomorphic sarcoma, which mimics what was once called pleomorphic malignant fibrous histiocytoma or fibrosarcoma, or
(2) Low-grade sarcoma, mimicking well-differentiated fibrosarcoma, low-grade myxofibrosarcoma or fibromatosis. Divergent differentiation occurs in 1/4 of cases and includes rhabdomyosarcomatous, leiomyosarcomatous, osteo-chondrosarcomatous or angiosarcomatous areas.

Clinical findings
Legs (e.g., popliteal fossa and medial thigh), retroperitoneal, perirenal, mesenteric region, shoulder.

Prognosis
Despite their high-grade appearance, DDLs tend to be less aggressive than other types of high-grade pleomorphic sarcomas: local recurrence in 40%, metastases in 10%. Location is the single most important prognostic factor; retroperitoneal DDLs fare far worse than those located on the extremities.

DiffDx
Any high-grade or pleomorphic sarcoma should be considered, as well as metastatic poorly-differentiated carcinoma, melanoma, or lymphoma.

Genetics
Ring or giant-marker chromosomes due to an amplification of chromosome 12q13-15, which results in the amplification of one or more genes in the region, including HMGA2, MDM2, SAS, GLI, CHOP, CDK4.

Mentioned in

References in periodicals archive

Dedifferentiated liposarcoma (DL) most commonly arises de novo, but may also arise within a recurrent WDL.

Dedifferentiated Liposarcoma With Myofibroblastic Differentiation

Dedifferentiated liposarcoma arising in the background of well-differentiated liposarcoma, with MDM2 gene amplification detected on fluorescent in-situ hybridization (FISH) testing.

Dedifferentiated liposarcoma of the hypolarynx

Among the poster presentations will be clinical results from the Phase 2 portion of the company's Phase 2/3 SEAL study evaluating selinexor, its lead, oral SINE compound, in patients with advanced unresectable dedifferentiated liposarcoma. The remaining posters will highlight data from ongoing investigator-sponsored trials evaluating selinexor in combination with approved anti-cancer agents in hematologic and solid tumor malignancies.

Karyopharm to present Selinexor Phase 2/3 SEAL data at ASCO

Differential diagnosis of atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma: Utility of p16 in combination with MDM2 and CDK4 immunohistochemistry.

A rare cause of dysphagia: Pyriform sinus atypical lipomatous tumor

Cabillic et al., "Differential diagnosis of atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma: utility of p16 in combination with MDM2 and CDK4 immunohistochemistry," Human Pathology, vol.

The Value of MRI in Distinguishing Subtypes of Lipomatous Extremity Tumors Needs Reassessment in the Era of MDM2 and CDK4 Testing

At the same time, the histopathologic examination of the atrial mass showed a high-grade sarcoma consistent with dedifferentiated liposarcoma. The tissue exhibited spindle cells with pleomorphism, multinucleated giant cells, and inflammatory cells.

Cardiac Dedifferentiated Liposarcoma Requiring a Mitral Valve Replacement Complicated by Severe Paravalvular Leak: A Rare Case Report with Literature Review

Liposarcoma is the most frequent histological subtype, and well-differentiated liposarcoma (WDL) and dedifferentiated liposarcoma (DDL) account for 90% of retroperitoneal liposarcomas [2].

Spinal Metastasis of Well-Differentiated Liposarcoma Component in Retroperitoneal Dedifferentiated Liposarcoma Treated by Minimally Invasive Surgery

Guillou et al., "MDM2 and CDK4 immunostainings are useful adjuncts in diagnosing well-differentiated and dedifferentiated liposarcoma subtypes: a comparative analysis of 559 soft tissue neoplasms with genetic data," American Journal of Surgical Pathology, vol.

Undifferentiated Pleomorphic Sarcoma of Pancreas: A Case Report and Review of the Literature for the Last Updates

Fletcher, "Dedifferentiated liposarcoma: clinicopathologic analysis of 32 cases suggesting a better prognostic subgroup among pleomorphic sarcomas," The American Journal of Surgical Pathology, vol.

Myxoid Liposarcoma: Prognostic Factors and Metastatic Pattern in a Series of 148 Patients Treated at a Single Institution

Dedifferentiated liposarcoma with rhabdomyoblastic differentiation in an 8-year-old girl.

Sclerotic Liposarcoma in the Deep Temporal Space of a 7-year-old Child

Marino-Enriquez, "STAT6 is amplified in a subset of dedifferentiated liposarcoma," Modern Pathology, vol.

Giant Perineal Solitary Fibrous Tumor: A Rare Case Report

Dedifferentiated liposarcoma of the lower extremity with low-grade dedifferentiation and low-grade osteosarcomatous component.

Liposarcoma pleomorfico, reporte de caso