A new classification of lymphoma has been published in 2001 under the direction of the World Health Organisation. This classification is based on a consensus between experts in haematopathology, haematology and oncology involved in management of lymphoma. Around 40 entities are described on the basis of morphology, immunophenotype, genetic and clinical presentation. Lymphomas and lymphoid leukaemias are gathered because tumour masses and leukaemic phases are present in numerous entities. This classification differentiates B-cell lymphomas from T/NK (natural killer) cell lymphomas. Grading the different lymphomas into low grade or high grade is no more required in this classification.