Soft tissue sarcomas (STSs) comprise ∼80 entities defined by the World Health Organization (WHO) classification based on a combination of distinctive morphological, immunohistochemical and molecular features.1 These ESMO–EURACAN–GENTURIS (European Society for Medical Oncology; European Reference Network for Rare Adult Solid Cancers; European Reference Network for Genetic Tumour Risk Syndromes) Clinical Practice Guidelines (CPGs) will cover STSs, with the exception of gastrointestinal stromal tumours (GISTs) that are covered in the ESMO–EURACAN–GENTURIS GIST CPGs.2 EURACAN and GENTURIS are the European Reference Networks connecting European institutions, appointed by their governments, to cover rare adult solid cancers and genetic cancer risk syndromes, respectively. Extraskeletal Ewing sarcoma, round cell sarcoma with EWSR1-non-ETS fusion and sarcomas with CIC rearrangements and BCOR genetic alterations are covered by the ESMO–EURACAN–GENTURIS–ERN PaedCan (European Reference Network for Paediatric Oncology) bone sarcomas CPG.3 Kaposi's sarcoma, embryonal and alveolar rhabdomyosarcoma are not discussed in this manuscript, while pleomorphic rhabdomyosarcoma is viewed as a high-grade, adult-type STS. Finally, extraskeletal osteosarcoma is also a considered a high-grade STS, whose clinical resemblance with osteosarcoma of bone is doubtful. The methodology followed during the consensus meeting is specified at the end of the manuscript in a dedicated paragraph
