Leukemic anaplasias reflecting physiologic cytogenesis of myeloid system

Naphthol AS-D chloroacetatesterase activity in peripheral blood granulocytes is confined to neutrophils which are all positive and to a minor part of monocytes. Its occurance in eosinophils and basophils indicate a myeloproliferative disease. This chemical property can reliably be applied to separate neoplastic from reactive forms of quantitative and qualitative leukocyte alterations. The developmental line of this specific myeloid cellular attribut has been presented to elucidate its diagnostic significance and its validity as proof for existence of a common promyelocyte from which neutrophils, monocytes, basophils and eosinophils originate.