Liposarcoma(LS) represents the most common soft-tissue sarcoma of adults and occurs most often in the thigh and retroperitoneum. LSs are subclassified into well-differentiated, myxoid, round cell, and pleomorphic types. The myxoid type, the most common subtype, accounts for approximately 40% to 54% of all liposarcomas. The karyotypic hallmark of myxoid LS is the t(12;16)(q13;p11), present cytogenetically in >90% of the cases. The translocation leads to the fusion of the DDIT3(CHOP) and FUS(TLS) genes at 12q13 and 16p11, respectively, and the generation of a FUS-DDIT3 hybrid protein. In 4 cases of myxoid LS, a variant chromosomal translocation has been described, t(12;22), in which DDIT3 fuses instead with EWSR1(EWS), a gene highly related to TLS.
