Soft Tissues: Lipoma / benign lipomatous tumors

2000-05-01   Nils Mandahl 

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

Summary

Note

lipomas are benign adipose tissue tumors with many subtypes, constituting one-third of all soft tissue tumors

Classification

Classification

  • Ordinary lipoma: the solitary, ordinary lipomas represent the most common soft tissue tumors, with subcutaneous tumors being much more common than the deep-seated ones
    Epidemiology: the incidence of lipomas is about one in 1000 inhabitants per year, but is probably underestimated since many lesions cause few problems; they occur most frequently between 30 and 70 years of age, with a peak incidence between 40 and 60 years
    Clinics: solitary lipomas are slow-growing masses, most frequently located in the upper back, neck, shoulder, abdomen, and the proximal portions of the extremities
    Evolution: surgery is required primarily when the tumors reach large size and cause cosmetic problems or complications due to their anatomical site; there is no risk of progression to malignancy, and recurrences are rare after shelling-out
  • Angiolipoma: angiolipomas show characteristic histological features and occur primarily as subcutaneous, painful nodules; multiple lesions are much more common than solitary ones; they are usually smaller than solitary, ordinary lipomas and present at an earlier age, with the dominating site being the forearm; an increased familial incidence has been noted
  • Spindle cell/ pleomorphic lipoma: the characteristic feature of spindle cell lipoma is the replacement of mature fat by collagen-forming spindle cells; these rare tumors typically occur subcutaneously in the neck and shoulders of men aged 45 to 65 years
    pleomorphic lipoma probably represents a highly pleomorphic variant of spindle cell lipoma and show similar clinical features;
    both of these types of lesions may be confused with liposarcoma
  • Lipoblastoma: lipoblastoma is a tumor of the infancy; most tumors occur before three years of age and may occasionally be seen already at birth; the site is primarily the upper and lower extremities; there may be a close resemblance to myxoid liposarcoma
  • Hibernoma: hibernoma is chiefly a tumor of adults, although in average occurring at lower ages than solitary, ordinary lipomas; the most common sites are the scapular and interscapular regions, mediastinum and upper thorax
  • Angiomyo-lipoma: angiomyolipoma is a hamartomatous lesion in the kidneys of adult patients, with a preponderance of women
  • Chondroid lipoma: chondroid lipoma is a rare tumor occurring in the subcutis or muscle of adults; it may be confused with liposarcoma and chondrosarcoma, and shows microscopic features of both lipoma and hibernoma
  • Cytogenetics

    Cytogenetics morphological

    Chondroid lipoma: a cytogenetically identical rearrangement, t(11;16)(q13;p13), found in the only two cases reported indicate that this is a recurrent aberration

    Bibliography

    Pubmed IDLast YearTitleAuthors
    104481171999Fusion genes in solid tumors.Aman P et al
    88248031996Genomic characterization of human HMGIC, a member of the accessory transcription factor family found at translocation breakpoints in lipomas.Ashar HR et al
    76067861995Disruption of the architectural factor HMGI-C: DNA-binding AT hook motifs fused in lipomas to distinct transcriptional regulatory domains.Ashar HR et al
    75341151995Translocation t(3;12)(q28;q14) in parosteal lipoma.Bridge JA et al
    93988691997Chromosome analysis in angiomyolipoma.Dal Cin P et al
    13770031992Cytogenetic analysis of renal angiomyolipoma.Debiec-Rychter M 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
    76802181993Cytogenetic findings in pediatric adipose tumors: consistent rearrangement of chromosome 8 in lipoblastoma.Fletcher JA et al
    103938371999Hibernomas are characterized by homozygous deletions in the multiple endocrine neoplasia type I region. Metaphase fluorescence in situ hybridization reveals complex rearrangements not detected by conventional cytogenetics.Gisselsson D et al
    91690351997Chromosomal aberration in lipoblastoma: a case with 46,XX,ins(8;6)(q11.2;q13q27).Kanazawa C et al
    87916791996Cytogenetics and molecular genetics of bone and soft tissue tumors.Mandahl N et al
    75156631994Cytogenetic aberrations in 188 benign and borderline adipose tissue tumors.Mandahl N et al
    77982941994A new cytogenetic subgroup in lipomas: loss of chromosome 16 material in spindle cell and pleomorphic lipomas.Mandahl N et al
    81117401994Involvement of 10q22 and 11q13 in hibernoma.Meloni AM et al
    94030601997Identification of new translocation breakpoints at 12q13 in lipomas.Merscher S et al
    80564461994Hibernomas are characterized by rearrangements of chromosome bands 11q13-21.Mertens F et al
    84536401993Chromosome 12 breakpoints are cytogenetically different in benign and malignant lipogenic tumors: localization of breakpoints in lipoma to 12q15 and in myxoid liposarcoma to 12q13.3.Mrózek K et al
    97729071998Translocation (11;14)(q13;q32) and overexpression of cyclin D1 protein in a CD23-positive low-grade B-cell neoplasm.Nanjangud G et al
    88124231996LPP, the preferred fusion partner gene of HMGIC in lipomas, is a novel member of the LIM protein gene family.Petit MM et al
    103290121999LHFP, a novel translocation partner gene of HMGIC in a lipoma, is a member of a new family of LHFP-like genes.Petit MM et al
    97729041998Expression of reciprocal fusion transcripts of the HMGIC and LPP genes in parosteal lipoma.Petit MM et al
    20957041990Cytogenetic analysis of a rare case of pediatric myxolipoma.Peulve P et al
    95987961998The t(3;12)(q27;q14-q15) with underlying HMGIC-LPP fusion is not determining an adipocytic phenotype.Rogalla P et al
    76704941995Recurrent rearrangements in the high mobility group protein gene, HMGI-C, in benign mesenchymal tumours.Schoenmakers EF et al
    91309911997Cytogenetic analysis of subcutaneous angiolipoma: further evidence supporting its difference from ordinary pure lipomas: a report of the CHAMP Study Group.Sciot R et al
    97636521998The cytogenetic and molecular characterization of benign and malignant soft tissue tumors.Sreekantaiah C et al
    93527901997Overrepresentation of 1q21-23 and 12q13-21 in lipoma-like liposarcomas but not in benign lipomas: a comparative genomic hybridization study.Szymanska J et al
    92127291997Expression of HMGI-C and HMGI(Y) in ordinary lipoma and atypical lipomatous tumors: immunohistochemical reactivity correlates with karyotypic alterations.Tallini G et al
    83302721993A case report of fibrolipoma with t(12;16)(q13;q24).Tayyeb MT et al
    99501681999Cytogenetic and cytologic features of chondroid lipoma of soft tissue.Thomson TA et al
    95303391998Comparison of chromosomal patterns with clinical features in 165 lipomas: a report of the CHAMP study group.Willén H et al

    External Links

    Citation

    Nils Mandahl

    Soft Tissues: Lipoma / benign lipomatous tumors

    Atlas Genet Cytogenet Oncol Haematol. 2000-05-01

    Online version: http://atlasgeneticsoncology.org/solid-tumor/5050/soft-tissues-lipoma-benign-lipomatous-tumors