Table of Contents

1 Introduction and Historical Aspects.- 2 Clinical Aspects.- 2.1 Clinical features.- 2.1.1 Epidemiology.- 2.1.2 Clinical features.- 2.2 Laboratory features.- 2.2.1 Haematology.- 2.2.2 Other clinical laboratory investigations.- 2.3 Prognosis: staging systems.- 3 Pathology.- 3.1 Bone marrow.- 3.2 Spleen.- 3.3 Liver.- 3.4 Lymph nodes.- 3.5 Other blood cells.- 3.5.1 Monocytes.- 3.5.2 T cells.- 3.5.3 Other haemic cells.- 3.6 Viruses and HCL.- 4 Diagnosis and Hairy-like Disorders.- 4.1 The diagnosis of typical HCL.- 4.2 Diagnosis when few abnormal cells are present.- 4.3 Diagnosis of HCL in the presence of atypical clinical or pathological features.- 4.4 Variant forms of HCL and closely related conditions.- 4.5 Atypical and rare presentations.- 5 Treatment: Mechanisms.- 5.1 Mechanism of action of splenectomy.- 5.2 The mechanism of action of ?IFN.- 5.2.1 Indirect effects.- 5.2.2 ‘Direct’ anti-proliferative activity.- 5.2.3 Modification of intracellular signals by ?IFN.- 5.2.4 Altered differentiation/activation state.- 5.3 Mechanism of action of the purine analogue drugs.- 5.3.1 Normal purine metabolism in lymphoid cells: the role of adenosine deaminase.- 5.3.2 Adenosine deaminase function in the presence of purine analogue drugs.- 5.3.3 Action of purine analogue drugs on malignant cells.- 6 Treatment: Practical Considerations.- 6.1 When should treatment be commenced?.- 6.2 Splenectomy.- 6.2.1 Therapeutic value of splenectomy.- 6.3 Interferon.- 6.3.1 Therapeutic activity of IFN in HCL.- 6.3.2 Problems with IFN therapy.- 6.3.3 Alternative strategies.- 6.4 Purine analogue drugs: DCF, CDA and fludarabine.- 6.4.1 Therapeutic activity of DCF.- 6.4.2 Therapeutic activity of CDA.- 6.4.3 Fludarabine.- 6.4.4 Choice of purine analogue drug in HCL.- 6.5 The use of colony-stimulating factors in HCL.- 6.6 Overview of therapeutic options.- 6.7 Treatment after failure of primary treatment option.- 6.8 Other treatment options.- 7 The Hairy Cell.- 7.1 Cytology.- 7.2 Cytochemistry.- 7.2.1 Tartrate-resistant acid phosphatase (TRAP).- 7.2.2 Other cytochemical techniques.- 7.3 Cytogenetics.- 7.3.1 Frequency of karyotypic abnormalities.- 7.3.2 Specificity of chromosomal changes.- 7.3.3 Possible significance of karyotypic changes in HCL.- 7.4 Ultrastructure.- 7.4.1 Transmission electron microscopy.- 7.4.2 Scanning electron microscopy.- 7.5 Nature of the malignant cell.- 7.5.1 Developmental stage: evidence from immunoglobulin studies.- 7.5.2 Developmental stage: evidence from immunophenotypic studies.- 7.5.3 Developmental stage: other approaches.- 7.6 Membrane, cytoskeletal organisation and signalling.- 7.6.1 Membrane.- 7.6.2 Cytoskeleton.- 7.6.3 Signalling.- 7.7 Response to cytokines.- 7.7.1 Low molecular weight B-cell growth factor.- 7.7.2 Tumour necrosis factor.- 7.7.3 Interleukin-2.- 7.7.4 Other interleukins.- 7.7.5 Myeloid growth factors.- 7.8 Adhesion and tissue localisation.- 7.8.1 Non-integrin adhesion receptors.- 7.8.2 Integrins.- 7.8.3 Adhesion molecules and HC behaviour.- 7.9 Cell survival and cell death.- Appendices.- Appendix A: Tartrate-resistant acid phosphatase (TRAP).- Appendix B: CD-antigen expression by HCs.- References.