Atypical Lipomatous Tumor / Well-differentiated Liposarcoma
High power view of an ALT/WDL showing scattered atypical stromal cells in sclerotic bands traversing between adipocytes. Majority of the atypical lipomatous tumors / well-diff. liposarcomas are characterized cytogenetically by supernumerary ring or giant marker chromosomes resulting in the amplification of 12q13-15 region. Several genes, including MDM2 and CDK4 are amplified as a result.