The lymphoma classification used in this section is based on the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues published in 2008. Some of the rare esoteric entities have not been mentioned since good examples are not available in our collection. The basic principles underlying the WHO 2008 Classification are the same as those used in the Revised European American Lymphoma (REAL) classification published by the International Lymphoma Study Group in 1994. The neoplasms are divided into B-cell, T-cell, and NK-cell categories based on lineage. In addition, there is further subdivision into precursor lymphoid neoplasms and those derived from mature lymphoid cells.