Real classification

Acronym for Revised European-American Lymphoma (R.E.A.L.) Classification",

Malignant tumours are usually classified according to their cellular origin. For a long time it was not possible to successfully apply this principle to malignant lymphomas. This only changed with the clarification of the cellular composition of the lymphatic tissue and the development of methods (immunohistology) with which the different cell types of the lymphatic system could be reliably differentiated from each other. In the meantime, it has been convincingly shown that the cellular origin determines the morphological and clinical features of most lymphoma diseases to a large extent and thus represents a viable basis for the classification of the majority of malignant lymphomas.

For decades, there have been competing and hardly comparable classifications of malignant lymphomas in the specialist literature. The Kiel Classification was used in German-speaking Europe and the"Working Formulation" mainly in the USA.

At the beginning of the 1990s, this unsatisfactory situation was overcome when pathologists from both continents developed a new lymphoma classification, the so-called"Revised European-American Lymphoma (R.E.A.L.-) Classification", based on current scientific data. The R.E.A.L. classification focused on the definition of distinct lymphoma diseases that can be diagnosed with high reproducibility. For this purpose, not only morphological and clinical but also immunophenotypic and molecular genetic characteristics were used. An international panel of pathology experts appointed by the World Health Organization (WHO) has updated the R.E.A.L. classification and published it under the title "WHO Classification of Malignant Lymphomas" (2001).

1. S. E. Coupland et al, "Lymphatic system and differentiation of B and T lymphocytes", The pathologist 21 (2000) 2, 106-112.
2. H. Stein, "The new WHO classification of malignant lymphomas", Der Pathologe 21 (2000) 2, 101-105.