Small B-cell lymphoproliferative disorders: an overview of diagnostic approach

Despite their common origin from the B-cell mature lymphoid system, small B-cell lymphomas/leukaemias represent in fact an heterogeneous group of diseases. Recent advances in immunohistochemistry and molecular techniques have improved our knowledge of the immune system and lymphoid neoplasms. An international consensus has been recently reached among pathologists and clinicians, that recognises clinico-pathological entities which are defined by a combination of morphological, immunophenotypical, genetic and clinical features. In each entity, a range of histological grade and clinical aggressiveness can be encountered. Recognition of these entities, combined with clinical prognostic factors has clinical implications in terms of response to treatment and prognosis. The purpose of this paper is to focus on a practical approach, either clinical or pathological, of the diagnosis of small B-cell lymphoma/leukaemia.