The diagnosis is made after a complete blood count, a routine blood test. The absolute neutrophil count in this test will be below 500, and can reach 0 cells/mm³. Other kinds of blood cells are typically present in normal numbers. To formally diagnose<unk> , other pathologies with a similar presentation must be excluded, such as aplastic anemia, paroxysmal nocturnal hemoglobinuria, myelodysplasia and leukemias. This requires a bone marrow examination that shows normocellular (normal amounts and types of cells) blood marrow with underdeveloped promyelocytes. These underdeveloped promyelocytes, if fully matured, would have been the missing granulocytes. Classification The term<unk> " derives from the Greek: a, meaning without; granulocyte, a particular kind of white blood cell (containing granules in its cytoplasm); and osis, meaning condition esp. disorder. Consequently,<unk>  is sometimes described as "no granulocytes", but a total absence is not required for diagnosis. However, "-osis" is commonly used in blood disorders to imply cell proliferation (such as in "leukocytosis"), while "-penia" to imply reduced cell numbers (as in "leukopenia"); for these reasons, granulocytopenia is a more etymologically consistent term, and as such, is sometimes preferred to<unk> " (which can be misinterpreted as "agranulocyt-osis", meaning proliferation of agranulocytes (i.e. lymphocytes and monocytes). Despite this,<unk> " remains the most widely used term for the condition. The terms<unk> , granulocytopenia and neutropenia are sometimes used interchangeably.<unk>  implies a more severe deficiency than granulocytopenia. Neutropenia indicates a deficiency of neutrophils (the most common granulocyte cell) only. To be precise, neutropenia is the term normally used to describe absolute neutrophil counts (ANCs) of less than 500 cells per microlitre, whereas<unk>  is reserved for cases with ANCs of less than 100 cells per microlitre. The following terms can be used to specify the type of granulocyte referenced: * Inadequate numbers of neutrophils: neutropenia (most common) * Inadequate numbers of eosinophils: eosinopenia (uncommon) * Inadequate numbers of basophils: basopenia (very rare) In a general sense the pathogenesis of neutropenia can be divided into two categories; * Inadequate or ineffective formation of granulocytes. This can be due to bone marrow failure associated with aplastic anemia, leukemia, or chemotherapeutic agents. There can also be isolated neutropenias where only differentiated granulocyte precursors are affected as in the case of neoplastic proliferation of cytotoxic T cells or NK cells * Accelerated destruction of neutrophils. Immune-mediated reactions to neutrophils which can be caused by drugs. An enlarged spleen can lead to splenic sequestration and accelerated removal of neutrophils. Utilization of neutrophils can occur in infections
Agranulocytosis
Granulocytosis
Febrile neutropenia
Leukopenia
Lycopenemia
Cytopenia
Cyclic neutropenia
Pythiosis