An immunocytochemical study on the distribution of ferritin and other markers in 36 cases of malignant histiocytosis.

The distribution of ferritin in 36 autopsy cases of malignant histiocytosis was investigated by immunocytochemical staining, together with the detection of alpha 1-antichymotrypsin, alpha 1-antitrypsin, lysozyme, S-100 protein, and ricinus communis agglutinin in the consecutive sections. The results showed that ferritin-positive tumor cells were present in every case. The quantity of cellular ferritin in well-differentiated histiocytes was higher than that in atypical histiocytes. Double labeling showed that ferritin and alpha 1-antichymotrypsin might be located either in one tumor cell or in separate cells. Our data suggest that ferritin may be a tumor associated antigen in malignant histiocytosis, playing a regulatory role for tumor cell differentiation.