Summary
Two cases of malignant mixed tumor of skin were studied, one of which demonstrated regional metastasis. The immunohistochemical features of these 2 neoplasms and of the 2 malignant mixed tumors previously described in Western Australia indicate that these neoplasms show eccrine differentiation and suggest their origin from both the secretory and ductal segments of the gland. The histological criteria of malignancy are discussed, with particular reference to those features which indicate malignant potential in neoplasms which otherwise lack overt morphological criteria of malignancy.