- A type of white blood cell, also called a macrophage, that is created by the bone marrow. They usually stay in place, but when histiocytes are stimulated by infection or inflammation they become active, attacking bacteria and other foreign matter in the body. See also histiocytosis.
* * *A tissue macrophage; the class includes hepatic Kupffer cells, alveolar macrophages, giant cells of granulomas, osteoclasts, and dermal Langerhans cells. These cells derive from precursors that normally reside in bone marrow but migrate through the bloodstream to egress into tissues for final differentiation. SYN: histocyte. [histio- + G. kytos, cell]- cardiac h. a large mononuclear cell found in connective tissue of the heart wall in inflammatory conditions, especially in the Aschoff body. The ovoid nucleus contains a central chromatin mass appearing as a wavy bar in longitudinal section. SYN: Anitschkow cell, Anitschkow myocyte, caterpillar cell.- sea-blue h. a h. containing cytoplasmic granules that stain bright blue with hematologic stains such as Wright-Giemsa; found in bone marrow and in the spleen, associated with hepatosplenomegaly and thrombocytopenic purpura and in other blood diseases.
* * *his·tio·cyte 'his-tē-ə-.sīt n MACROPHAGE esp a nonmotile macrophage of extravascular tissues and esp. connective tissue
* * *n.
* * *his·tio·cyte (hisґte-o-sīt″) [histio- + -cyte] macrophage. histiocytic adj
Medical dictionary. 2011.