While the majority of LGFMS cases are characterized by a FUS-CREB3L1 fusion, both FUS-CREB3L2 and EWSR1-CREB3L1 fusions were recently demonstrated in a small number of LGFMS and SEF/LGFMS hybrid tumors.
Our results indicate that EWSR1 and CREB3L1 rearrangements are predominant over FUS and CREB3L2 rearrangements in pure SEF, highlighting that SEF and LGFMS are different tumor types, with different impacts on patient outcome.
Recently, a link has been suggested between SEF and low-grade fibromyxoid sarcoma (LGFMS) on the basis of the finding of the characteristic translocation t(7;16) (FUS-CREB3L2) of LGFMS in a small number of studied cases of SEF.