Modern histological classification of low grade B-cell lymphomas.

The classification of lymphomas has been one of the most controversial areas of tumour pathology. Most of the difficulties in development of sophisticated classifications have been a direct consequence of the biological diversity inherent in this group of neoplasms; a reflection of the physiological complexity of lymphocyte development and differentiation. The new World Health Organisation (WHO) lymphoma classification identifies individual clinicopathological entities; integrating morphology, immunophenotype, genotype, normal cell counterpart/cell of origin and clinical features. The degree to which these five characteristics contributes to the definition of individual entities differs from one entity to the other. This classification has received worldwide acceptance in the short term it has been available and has become the gold standard in lymphoma diagnosis.