Langhans-type and foreign-body-type multinucleated giant cells in cutaneous lesions of sarcoidosis

Multinucleated giant cells are characteristic of a monocyte-macrophage lineage in sarcoidosis and consist of two types of cells: Langhans-type with an arcuate arrangement of nuclei and a foreign-body type with random arrangement of nuclei. To compare these cells in the cutaneous lesions of sarcoidosis, we histologically and immunohistologically examined multinucleated giant cells in 25 scar infiltrations (cutaneous sarcoidosis with foreign bodies) and 30 cutaneous lesions of sarcoidosis without foreign bodies. Regardless of the presence or absence of foreign bodies, the cutaneous lesions had both types of multinucleated giant cells, usually with a predominance of the Langhans-type, although the numbers of total multinucleated giant cells were higher in scar infiltrations than in cutaneous sarcoidosis without foreign bodies, suggesting that their frequency is influenced by the microenvironment in sarcoidal lesions such as the presence of foreign bodies. Immunohistochemical studies using surface antigens of monocyte-macrophage lineage cells and adhesion molecules indicated that both types of multinucleated giant cells are formed from monocytes rather than tissue macrophages and are phenotypically the same cells with different distributions of nuclei.