Immunohistochemical and ultrastructural studies on histiocytosis in children.

Thirty-four cases of eosinophilic granulomas, 18 cases of diffuse histiocytosis-X, 2 cases of Letterer-Siwe-like syndrome with immunodeficiency, 4 cases of malignant histiocytosis and virus associated hemophagocytic syndrome were studied. On paraffin section, S100 protein, lysozyme, alpha-1-anti-trypsin, alpha-1-antichymotrypsin, alpha-2-macroglobulin, Transferrin, Ferritin, peanuts agglutinin, Concanavalin-A, and dolichos biflorus associated antigen were stained by the immunoperoxidase method. In a few fresh materials, T-cell subpopulation by use of monoclonal antibodies (OKT-3, 4, 6, and OK-M1) was examined by the immunoperoxidase method. Two types of Langerhans' cells were found, one is positive for Ferritin and alpha-2-macroglobulin in diffuse histiocytosis-X cells, and another is negative for them in both eosinophilic granulomas. Diffuse histiocytosis-X cell resembled the transformed type of Langerhans cell more than eosinophilic granuloma cells in cellular differentiation. It seemed that the term prolangerhans' cell proliferation disorder might be responsible for it.