noun, plural: giant cells
A giant cell is an unusually large cell with several nuclei. It is often used to refer to a cell forming a granuloma. Granuloma is a chronic inflammatory lesion comprised of giant cells and other cell types (e.g. macrophages, lymphocytes, fibroblasts, etc.). Giant cells may arise from infections, such as HIV, tuberculosis, herpes, etc. They may be formed from the union of certain cells.
Touton giant cell is an example of a giant cell. It is a xanthoma cell containing multiple nuclei that form a ring. It is formed by the fusion of epithelioid macrophages. Another example of a giant cell is the Langhans giant cell, which is also formed by the fusion of epithelioid macrophages but the nuclei are peripherally located. The latter is associated with the central part of early tubercular lesions. Reed-Sternberg cell, foreign-body giant cell, and giant cell arteritis are other types of giant cells.