NCIt definition : A rare bone marrow disorder characterized by a marked decrease or complete absence
of megakaryocytes with preservation of all other hematopoietic cell lineages. Causes
include toxins, viruses, drugs, and humoral and cell-mediated suppression of megakaryocytopoeisis.
It usually presents with bleeding, severe thrombocytopenia, and absence of splenomegaly.
It is often misdiagnosed as immune thrombocytopenic purpura (ITP).;