low grade fibromyxoid sarcoma
A low grade, late-metastasizing variant of fibrosarcoma characterized by alternating fibrous and myxoid areas and a whorling growth pattern. The neoplastic cells have a spindle morphology, and lack hyperchromasia or significant nuclear atypia. Approximately 40% of cases show the focal presence of collagen rosettes. A t(7;16)(q33;p11) translocation has been identified in the majority of cases, associated with the presence of FUS-CREB3L2 fusion protein. Rare cases carry the t(11;16)(p11;p11) translocation which is associated with the presence of the FUS-CREB3L1 fusion protein.