Herein, we report for the first time a novel secondary clonal translocation, t(2;4) (q23;p14) in addition to t(12;16)(q13; p11.2) in a 30-year-old woman with myxoid liposarcoma on the left posterior thigh region without any prior chemoradiation therapy.
Myxoid liposarcoma (LS), the most common subtype of LS, is known to be characterized by the specific t(12;16) resulting in a TLS-CHOP fusion in almost all cases.
Circumstantial evidence suggests that genetic changes may lead to tumor progression within the myxoid liposarcoma tumors (MLTs) carrying non-random chromosomal translocation t(12;16).
Furthermore, six of the translocations, namely the t(11;22), t(21;22), and t(7;22) of Ewing's sarcoma, the t(12;22) of clear cell sarcoma, the t(12;16) of myxoid liposarcoma, and the t(11;22) of desmoplastic small round cell tumor, achieve this following a peculiar pattern, consisting in the fusion of a gene with an RNA-binding domain (EWS or TLS) with a transcription factor gene (FLI1, ERG, ETV1, ATF-1, CHOP, or WT1).
Thus, rearrangements of the CHOP gene appear to be specific for myxoid liposarcoma with t(12;16) and are not associated with lipoblastic differentiation.