The world health organization classification of lymphoid neoplasms

Abstract

The World Health Organization (WHO) classification of the lymphoid neoplasms updated in 2008 represents a worldwide consensus on lymphoma diagnosis and is based in two major principles: the stratification of neoplasms according to their cell lineage and their derivation of precursor or mature cells and the definition of non-overlapping distinct diseases that are clinically relevant. The identification of these diseases is based on a combination of morphology, immunophenotype, genetic, molecular, and clinical features. In addition to well-defined entities, the classification addresses open issues, such as provisional entities that correspond to categories for which there were insuf ficient evidence to support its recognition as distinct diseases at the time of publication and borderline categories with overlapping features between large B-cell lymphomas and Burkitt or Hodgkin lymphoma.