What are epithelioid histiocytes?
Epithelioid histiocytes (Epithelioid cells) are activated macrophages resembling epithelial cells: elongated, with finely granular, pale eosinophilic (pink) cytoplasm and central, ovoid nucleus(oval or elongate), which is less dense than that of a lymphocyte.
What is the function of epithelioid cells?
Epithelioid cells are cells of the mononuclear phagocyte system found in certain granulomas mainly associated with intense immunological activity. These cells show little phagocytic activity.
What cells are seen in granulomatous inflammation?
The granulomatous inflammatory response is a special type of chronic inflammation characterised by often focal collections of macrophages, epithelioid cells and multinucleated giant cells.
What are histiocytes give their function?
Histiocytes/macrophages are derived from monocytes and play an important role in the regulation of immune functions. They are involved in different aspects of host defense and tissue repair, such as phagocytosis, cytotoxic activities, regulation of inflammatory and immune responses, and wound healing.
What are epithelioid macrophages?
Epithelioid histiocytes are macrophages activated to develop characteristics of epithelial cells and form tight interdigitated junctions between their cell membranes (Ramakrishnan 2012).
Why macrophages are called histiocytes?
Macrophages and dendritic cells are derived from common bone marrow precursor cells that have undergone different differentiation (as histiocytes) under the influence of various environmental (tissue location) and growth factors such as GM-CSF, TNF and IL-4.
What is epithelioid granuloma?
Epithelioid granulomas are a feature of chronic cutaneous leishmaniasis and leishmania recidivans though they have also been described in around 30% of cases of acute leishmaniasis. Although most cases of nodular post kala azar dermal leishmaniasis are non-granulomatous, epithelioid granulomas are seen in some cases.
Are histiocytes white blood cells?
Histiocyte cells are a form of white blood cells that help the immune system destroy foreign materials and fight infection. The extra immune cells produced by this condition may form tumors, which can affect parts of the body like the bones and possibly spread to other areas.
What do epithelioid macrophages do?
Epithelioid cells have tightly interdigitated cell membranes in zipper-like arrays that link adjacent cells. This cells are central in the formation of granulomas, which are associated with many serious diseases. In granulomas, epithelioid cells perform the functions of delimiting.