S-100-protein-positive dendritic cells in nodular vasculitis.

We investigated the distribution of S-100-protein-positive dendritic cells in 20 cases of nodular vasculitis (erythema induratum Bazin). The cells were identified by immunohistochemical demonstration in paraffin sections. S-100-protein-positive dendritic cells were present in all cases and comprised up to 11% of the infiltrating cells in lymphohistiocytic areas (mean 3.7%). Because of the dendritic shape and the association with lymphocytes the cells are considered to represent T-zone histiocytes. Our findings suggest a possible role of delayed-type hypersensitivity in nodular vasculitis.