This report describes a malignant tumor of soft tissue which combined granular cells with an histologic pattern of malignant fibrous histiocytoma. Immunohistological and ultrastructural studies were performed. Neo-plastic cells were devoid of S-100 Protein but contained lysozyme. Ultrastructural findings showed granular cells containing numerous lysosomes and non-granular cells exhibiting fibroblastic and histiocytic differentiations. This lesion prompts us to consider either a malignant granular cell tumor or a malignant fibrous histiocytoma.