<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>An antiquated term referring to cases of systemic non-Hodgkin lymphomas which are composed of large, atypical neoplastic lymphoid cells and cases of hemophagocytic syndromes. In the past, cases of anaplastic large cells lymphoma were called malignant histiocytosis.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>