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

    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/favicon/apple-touch-icon.png