[Fourth edition of WHO classification tumours of soft tissue].

The new World Health Organization (WHO) classification of soft tissue tumours was published in 2013, 11years after the previous edition. This new classification includes several changes: newly included sections (gastrointestinal stromal tumors…), newly recognized entities (pseudomiogenic haemangioendothelioma, haemosiderotic fibrolipomatous tumour…), and new genetic and molecular data leading to better understanding and definition of tumours, and are useful as diagnostic tools. This brief review summarizes changes in this new edition of the WHO classification of tumours of soft tissue.