NR4A3 and extraskeletal myxoid chondrosarcoma: EMC constitutes a distinct genomic entity characterised by reciprocal translocation of fusion genes, most commonly EWS RNA Binding Protein 1 (EWSR1) in 22q12 with Nuclear Receptor Subfamily 4 Group A Member 3 (NR4A3) in 9q2-q31.1.