Myxoid Liposarcoma : Cytogenetics

Comments:
Molecular Cytogenetics: Both myxoid liposarcoma (LPS) and its higher-grade variant (previously called round cell LPS) harbor reciprocal translocation t(12;16)(q13;p11) resulting in FUS-DDIT3 fusion. DDIT3 is a transcription factor that blocks adipocyte terminal differentiation. In about 3% of myxoid LPS, there is translocation t(12;22)(q13;q13) and the partner gene for DDIT3 is EWSR1 instead of FUS. FUS-DDIT3 antibody is available for immunohistochemical detection. Additional genetic events in myxoid LPS include TERT promoter mutations (50% cases) and activating mutations in PI3K/mTOR pathway (25% cases).

Image source: Iwasaki H et al. Extensive lipoma-like changes of myxoid liposarcoma: morphologic, immunohistochemical, and molecular cytogenetic analyses. Virchows Arch (2015) 466:453–464 DOI 10.1007/s00428-015-1721-z; cropped from the original figure and used under Creative Commons Attribution license.