Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Hematolymphoid Tumours.

In 2017, the latest revision to the WHO Classification of Head and Neck Tumours will be released. Similar to the 2005 WHO, the codification of hematopoietic and lymphoid neoplasms of the head and neck is included within chapters pertaining to the nasal cavity and paranasal sinuses, the nasopharynx, the larynx, the oral cavity and oropharynx, the neck and the salivary glands. Herein, we describe both changes to the classification of hematolymphoid neoplasms of the head and neck since the 2005 WHO, as well as recent advances in our understanding of the underlying pathogenesis and molecular pathology of these neoplasms.