Although sporadic cases of neutropenia with distinctive morphological abnormalities have been described, there is no unifying set of morphological findings characteristic for cyclic, congenital or chronic idiopathic neutropenia. These diagnoses are made by excluding other causes and by observing patients and their symptoms over time. The diagnosis of cyclic neutropenia usually requires observation of counts approximately three times per week for about six to eight weeks. Congenital neutropenia is distinguished from immunoneutropenia of the newborn by its persistence after the first few weeks to months of life and by specific antibody tests. Congenital cases are generally subcategorized on the basis of associated physical findings and abnormalities in other organ systems. Chronic idiopathic neutropenia is also diagnosed by excluding infectious, malignant, premalignant and autoimmune disorders.