Abstract :
Keywords: Soft tissue; Sarcoma; Immunohistochemistry; Molecular genetics; Head and neck pathology Abstract The fifth (5th) edition of the World Health Organization (WHO) Classification of Head and Neck Tumors introduces a new chapter dedicated to soft tissue neoplasms commonly affecting the head and neck. While the diversity, rarity, and wide anatomic range of soft tissue tumors precludes a discussion of all entities that may be found in the head and neck, the addition of this new chapter to the head and neck "blue book" aims to provide a more comprehensive and uniform reference text, including updated diagnostic criteria, of mesenchymal tumor types frequently (or exclusively) arising at head and neck sites. Since publication of the previous edition in 2017, there have been numerous advances in our understanding of the pathogenesis of many soft tissue tumors which have facilitated refinements in tumor classification, identification of novel entities, development of diagnostic markers, and improved prognostication. This review will provide a focused discussion of the soft tissue tumors included in the 5th edition WHO Head and Neck classification, with an emphasis on updates. Author Affiliation: (1) Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, 75 Francis Street, 02115, Boston, MA, USA (2) Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada (3) Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada (a) vjo@bwh.harvard.edu Article History: Registration Date: 02/04/2022 Received Date: 12/10/2021 Accepted Date: 02/03/2022 Online Date: 03/21/2022 Byline: