Agranulocytosis rarely occures on its own, more often it exists as part of aplastic anemia.
Autoimmune myelopoiesis inhibition, autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus), tumorous diseases (systemic mastocytosis), drugs, toxins.
Bone marrow is hypocellular, with normal megakaryocytes and normal erythropoiesis. Myelopoiesis is significantly decreased or missing completely. Reactive lymphocytosis and plasmocytosis is usually present.