Two cases of malignant fibrous histiocytoma (MFH) of the breast are presented. The first case was a 63-year-old patient with MFH of myxoid type, the second case was a 79-year-old patient with MFH of pleiomorphic type. MFH is one of the most common tumors of the soft tissues, but its primary occurrence in the breast is rare. Immunohistochemical detection of antigens in the cytoplasm of histiocytes by antibdy LN 5 (Anti-Macrophage, BioGenex) can be helpful in rendering of the right diagnosis.

        Key words: malignant fibrous histiocytoma – breast – immunohistochemistry