Immunophenotyping in the diagnosis of chronic lymphoproliferative disorders. General Haematology Task Force of BCSH.

Introduction As in the acute leukaemias, immunophenotyping has been shown to be useful in the characterisation and classification of the chronic lymphoproliferative disorders.' 2 This term refers to a group of diseases caused by the clonal proliferation of B and T lymphocytes. Recognition of the various disease entities is essential because of major implications for prognosis and patient management. The diagnosis of the lymphoproliferative disorders requires use of multiple technologies including immunological markers, cell morphology and, in some cases, histopathology of the affected tissues and molecular and cytogenetic investigations.2 Immunophenotyping is a key laboratory test in the precise diagnosis of these conditions. This article discusses the role of immunological markers in the diagnosis and characterisation of the lymphoproliferative disorders and provides guidance on: (1) methodological aspects; (2) panels of markers useful for diagnostic purposes; (3) interpretation of the results and; (4) indications for immunophenotyping.