Principles of the revised European-American Lymphoma Classification (from the International Lymphoma Study Group).

The International Lymphoma Study Group has proposed a consensus classification for lymphoid neoplasms. Lymphoid neoplasms are defined as distinct biological entities, based on a combination of morphologic, immunophenotypic, genetic, and clinical features. Each distinct disease may have a range of histologic grade and clinical aggressiveness. Although many distinct diseases can now be recognized, three of them (follicular lymphoma, diffuse large B-cell lymphoma, and Hodgkin's disease) account for the majority of the cases seen in Europe and the USA. Recognition of distinct disease entities is essential in order to develop and test effective therapies.