Benign and Malignant Hematopoietic Diseases of the Head and Neck

The head and neck region is commonly involved with hematopoietic diseases. These lesions can be benign or malignant and involve lymph nodes or extranodal sites. Many non-Hodgkin and Hodgkin lymphomas involve head and neck lymph nodes as a part of systemic involvement. The current classification of lymphomas is the 2017 revision of the World Health Organization classification which is used in this chapter. These lymphomas are discussed briefly in this chapter and the reader is referred to other reference sources for a more complete discussion of these entities. In this chapter, we focus on benign and malignant diseases that are either common or unique to the head and neck region. Many benign diseases of the head and neck are caused by viral infection or autoimmune etiologies. A few types of lymphoma are particularly common in the head and neck and often involve extranodal sites. In this chapter, we discuss the various anatomic regions of the head and neck involved by lymphoma and specific types of lymphoma that have a preference for the head and neck region. We also review histiocytic and myeloid lineage neoplasms that can occur in this region. For each disease, we have focused on clinical and pathologic findings and the differential diagnosis with other entities. Molecular findings are mentioned where appropriate but are not the focus of this chapter.