S-100 protein in Langerhans cells, interdigitating reticulum cells and histiocytosis X cells

S-100 protein was immunohistochemically demonstrated in the cells of cases of histiocytosis X such as eosinophilic granuloma, Hand-Schüller-Christian disease and Letterer-Siwe disease. Its presence was also shown in Langerhans cells of the epidermis and interdigitating reticulum cells in the lymph node, spleen and thymus. S-100 protein was not found in epithelioid cells in sarcoidosis, phagocytic macrophages, or dendritic reticulum cells in germinal centers. S-100 protein might be a new immunohistochemical marker for the Langerhans cells, interdigitating reticulum cells and histiocytosis X cells.