histiocyte


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Related to histiocyte: Langerhans cell

histiocyte

 [his´te-o-sīt″]
macrophage. adj., adj histiocyt´ic.

his·ti·o·cyte

(his'tē-ō-sīt'),
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.
Synonym(s): histocyte
[histio- + G. kytos, cell]

histiocyte

(hĭs′tē-ə-sīt′)
n.
A macrophage or dendritic cell that is usually immobile and is found in organs and tissues.

his′ti·o·cyt′ic (-sĭt′ĭk) adj.

macrophage

A nonspecific immune defence cell that interacts with proteins and polysaccharide antigens, internalising and partially degrading them, and/or presenting the antigens to T cells in a major histocompatibility complex (MHC) context. Macrophages are involved in secretion, immune interaction with T and B cells and provide lymphokine receptors; once activated, macrophages are highly microbicidal and tumouricidal, often closely associated with the blood vessels, epithelium and mesothelium, which are appropriate sites for non-specific immunocytes.
 
Morphology
Large (15–80 µm in diameter), often with bleb-like or filiform pseudopodia; one (or rarely more) round to oval, occasionally indented nucleus; nuclear membrane is distinct; nuclear chromatin is fine with a reticular pattern; abundant, pale grey-blue, often granulated (coarse azurophilic granules) and vacuolated cytoplasm with phagocytosed material (RBCs, WBCs, platelets, nuclei, bacteria and remnants in native or degraded form).

his·ti·o·cyte

(his'tē-ō-sīt)
A macrophage present in connective tissue.
Synonym(s): histocyte.
[histio- + G. kytos, cell]

histiocyte

A fixed scavenging cell (phagocyte) found in connective tissue. Histiocytes are also known as reticuloendothelial cells and reticulum cells. A macrophage that does not migrate.

his·ti·o·cyte

(his'tē-ō-sīt)
A macrophage in connective tissue.
[histio- + G. kytos, cell]
References in periodicals archive ?
Histologically, almost all tissues examined were affected by a lymphohistiocytic infiltrate characterized by mature lymphocytes and benign histiocytes. Within these infiltrates, but more prominent in the bone marrow, lungs and spleen, hemophagocytosis was observed (Figure 1).
Rosai-Dorfman disease bears at least superficial resemblance to histiocytic sarcoma because of the presence of large histiocytes with abundant cytoplasm and emperipolesis.
Desmet, "Histiocytes in Sweet's syndrome," British Journal of Dermatology, vol.
Skin biopsy in Letterer-Siwe disease shows a proliferative reaction with extensive upper dermal infiltration and epidermal invasion with histiocytes, some of which are atypical, along with erythrocytes.
Three smears with at least 2 histiocytes demonstrating hemophagocytosis on each are suggested for HLH diagnosis, which were detected in both of our patients [7].
The treatment of these patients was basically in accordance with the histiocyte society LCH-III protocol with the treatment of isolated PLCH cases based on chemotherapy.[15] Furthermore, for some refractory patients, cladribine was found to improve respiratory function and reduce the size of cysts, even in patients with advanced disease.[16],[17]
Histological section revealed native architecture distortion by excessive numbers of large histiocytes with abundant foamy cytoplasm (Figure 1).
A proposed mechanism is cytokine activation following HHV6 or EBV infection leading to activation and accumulation of histiocytes, which is supported by the expression of HHV-6 antigens in abnormal histiocytes from RDD patients [2, 6, 8, 16].
LCH with an unknown etiology is a group of diseases in which atypical histiocytes cause damage locally or extensively as a result of their accumulation in various tissues such as skin, bone, lung, liver, lymph nodes, mucocutaneous tissues, and endocrine organs [6, 7].
Fibrous capsule consists of dense fibrosis, with an inner surface lined by pseudosynovia, consisting of a layer of histiocytes. When silicone particles get in contact with fibrous capsule, whatever the mechanism, an immune response could be generated from the host.
The lamina propria showed dense mixed inflammatory infiltrate comprising sheets of foamy histiocytes, neutrophils, eosinophils, lymphocytes and plasma cells.
Therefore, an orbital biopsy by ophthalmology was performed, revealing lymphoid tissue with histiocyte proliferation.