Immunophenotype analysis of malignant histiocytosis of the intestine

Five cases of malignant histiocytosis of the intestine and one case of true histiocytic lymphoma were studied using immunohistological techniques. In paraffin sections tumour cells in all cases were shown to contain alpha-1-antitrypsin and to express the leucocyte common antigen. Four of the five cases of malignant histiocytosis of the intestine and the case of histiocytic lymphoma expressed the epithelial membrane antigen. Cryostat sections in four cases of malignant histiocytosis of the intestine showed that most tumour cells reacted with anti-T cell monoclonal antibodies. Only a minority expressed a typical monocyte macrophage phenotype.