Soft Tissues: Liposarcoma / malignant lipomatous tumors

2000-05-01   Nils Mandahl 

1.Department of Clinical Genetics, University Hospital, Lund, Sweden



liposarcomas are adipose tissue tumors, including low-malignant to highly malignant subtypes, constituting 10-15% of soft tissue sarcomas



  • Well-differentiated liposarcoma: the well-differentiated liposarcomas are tumors of low grade malignancy that may recur locally but not metastasize; the terminolgy of subtypes is not straightforward; three related sybtypes have been distinguished: lipoma-like (the most common form), inflammatory, and sclerosing; other terms that have been suggested to describe at least subsets of these tumors are atypical lipoma and atypical lipomatous tumor
  • Myxoid liposarcoma / round cell liposarcoma: myxoid liposarcoma is the most common form of liposarcomas, constituting about half of the cases, with a relatively favorable prognosis; the much less common, and more aggressive round cell liposarcoma is regarded as a poorly differentiated variant of myxoid liposarcoma; pure round cell liposarcomas are very rare, and more often the tumors represent mixed liposarcomas with both myxoid and round cell components at different proportions; in recurrences the round cell component may increase
  • Pleomorphic liposarcoma: the pleomorphic liposarcomas are highly malignant tumors showing a disorderly growth pattern and extensive cellular pleomorphism
  • Clinics and Pathology


    the reported annual incidence of liposarcoma is in the range of 2.5 per million; liposarcomas are tumors of adult life with a median age of 55-60 years; patients younger than 15 years are rare; men are slightly more often affected than women


    the major sites are the lower extremities and the retroperitoneum; most tumors range from 5 to 10 cm in diameter, but much larger tumors are not rarely seen.


    the risk of distant metastases relate to the type and degree of histological differentiation; well-differentiated liposarcomas may occasionally dedifferentiate to highly malignant tumors that may metastasize


    the survival rates are primarily dependent on the histological type, and patients with well-differentiated and myxoid liposarcomas, on the one hand, fare much better than round cell and pleomorphic liposarcomas on the other hand


    Cytogenetics morphological

    Pleomorphic liposarcoma
    few cases have been cytogenetically characterized; they invariably show complex karyotypic changes, with no characteristic changes identified, and an extensive intratumor heterogeneity


    Pubmed IDLast YearTitleAuthors
    104481171999Fusion genes in solid tumors.Aman P et al
    89213631996Expression patterns of the human sarcoma-associated genes FUS and EWS and the genomic structure of FUS.Aman P et al
    12833161992Rearrangement of the transcription factor gene CHOP in myxoid liposarcomas with t(12;16)(q13;p11).Aman P et al
    90101021997Interphase cytogenetic analysis of myxoid soft tissue tumors by fluorescence in situ hybridization and DNA flow cytometry using paraffin-embedded tissue.Aoki T et al
    81252581994CHOP (GADD153) and its oncogenic variant, TLS-CHOP, have opposing effects on the induction of G1/S arrest.Barone MV et al
    92051001997HMGIC, the gene for an architectural transcription factor, is amplified and rearranged in a subset of human sarcomas.Berner JM et al
    85107581993Fusion of CHOP to a novel RNA-binding protein in human myxoid liposarcoma.Crozat A et al
    83538091993Cytogenetic and fluorescence in situ hybridization investigation of ring chromosomes characterizing a specific pathologic subgroup of adipose tissue tumors.Dal Cin P et al
    85791241996Correlation between clinicopathological features and karyotype in lipomatous tumors. A report of 178 cases from the Chromosomes and Morphology (CHAMP) Collaborative Study Group.Fletcher CD et al
    85273901995Comparative genomic hybridization analysis of human sarcomas: I. Occurrence of genomic imbalances and identification of a novel major amplicon at 1q21-q22 in soft tissue sarcomas.Forus A et al
    103691611999The structure and dynamics of ring chromosomes in human neoplastic and non-neoplastic cells.Gisselsson D et al
    99898221999Characteristics of genomic breakpoints in TLS-CHOP translocations in liposarcomas suggest the involvement of Translin and topoisomerase II in the process of translocation.Kanoe H et al
    78050341995Translocation t(12;16)(q13;p11) in myxoid liposarcoma and round cell liposarcoma: molecular and cytogenetic analysis.Knight JC et al
    83873911993p53 Mutation and MDM2 amplification in human soft tissue sarcomas.Leach FS et al
    75156631994Cytogenetic aberrations in 188 benign and borderline adipose tissue tumors.Mandahl N et al
    95950411998Nonrandom pattern of telomeric associations in atypical lipomatous tumors with ring and giant marker chromosomes.Mandahl N et al
    95916301998Cytogenetic analysis of 46 pleomorphic soft tissue sarcomas and correlation with morphologic and clinical features: a report of the CHAMP Study Group. Chromosomes and MorPhology.Mertens F et al
    93151041997Characteristic sequence motifs at the breakpoints of the hybrid genes FUS/CHOP, EWS/CHOP and FUS/ERG in myxoid liposarcoma and acute myeloid leukemia.Panagopoulos I et al
    98921061999Structure of the supernumerary ring and giant rod chromosomes in adipose tissue tumors.Pedeutour F et al
    90719981997Distinct mdm2/p53 expression patterns in liposarcoma subgroups: implications for different pathogenetic mechanisms.Pilotti S et al
    75038111993Fusion of the dominant negative transcription regulator CHOP with a novel gene FUS by translocation t(12;16) in malignant liposarcoma.Rabbitts TH et al
    88270231996Combined morphologic and karyotypic study of 59 atypical lipomatous tumors. Evaluation of their relationship and differential diagnosis with other adipose tissue tumors (a report of the CHAMP Study Group).Rosai J et al
    15681701992Cytogenetic findings in liposarcoma correlate with histopathologic subtypes.Sreekantaiah C et al
    102134971999GLI gene expression in bone and soft tissue sarcomas of adult patients correlates with tumor grade.Stein U et al
    88341711996Gains and losses of DNA sequences in liposarcomas evaluated by comparative genomic hybridization.Szymanska J et al
    87647411996Combined morphologic and karyotypic study of 28 myxoid liposarcomas. Implications for a revised morphologic typing, (a report from the CHAMP Group).Tallini G et al
    104496031999Identification of genes differentially expressed in TLS-CHOP carrying myxoid liposarcomas.Thelin-Järnum S et al
    89939821997Complexity of 12q13-22 amplicon in liposarcoma: microsatellite repeat analysis.Wolf M et al
    86809031995Inflammatory Bowel Disease Questionnaire: cross-cultural adaptation and further Boer AG et al

    External Links


    Nils Mandahl

    Soft Tissues: Liposarcoma / malignant lipomatous tumors

    Atlas Genet Cytogenet Oncol Haematol. 2000-05-01

    Online version: