The pathology of bone marrow failure.

An important indication for bone marrow investigation is the presence of bone marrow failure, which manifests itself as (pan)cytopenia. The causes of cytopenia are varied and differ considerably between childhood and adulthood. In the paediatric age group inherited bone marrow failure syndromes are important causes of bone marrow failure, but they play only a minor role in later life. This review gives a comprehensive overview of bone marrow failure disorders in children and adults. We classified the causes of bone marrow failure according to the main presenting haematological abnormality, i.e. anaemia, neutropenia, thrombocytopenia or pancytopenia. The following red cell disorders are discussed: red cell aplasia, sideroblastic anaemia, congenital dyserythropoietic anaemia, haemolytic anaemia, paroxysmal nocturnal haemoglobinuria, iron deficiency anaemia, anaemia of chronic disease and megaloblastic anaemia. The neutropenias occur in the context of Shwachman-Diamond syndrome (SDS), severe congenital neutropenia, cyclic neutropenia, immune-related neutropenia and non-immune neutropenia. In addition, the following causes of thrombocytopenia are discussed: congenital amegakaryocytic thrombocytopenia, thrombocytopenia with absent radii, immune-related thrombocytopenia and non-immune thrombocytopenia. Finally, we pay attention to the following pancytopenic disorders: Fanconi anaemia, dyskeratosis congenita, aplastic anaemia, myelodysplastic syndromes and human immunodeficiency virus (HIV) infection.