Abstract:Myxofibrosarcoma or myxoid variant of malignant fibrous histiocytoma (MFH) is one of the most common sarcomas in the extremities in adults and particularly in elderly patients. It is characterized by a high frequency of local recurrence. We report a patient with high grade myxofibrosarcoma infiltrating the striated muscle of the right forearm. On microscopic examination, the tumor lacked areas of necrosis and pronounced cellular pleomorphism. Immunohistochemically, the tumor cells showed intense reactivity to S-100 protein (PS 100) and discrete reactivity of desmin, CD34 and SMA. After surgery of the tumor, the patient received local radiotherapy and chemotherapy. One year after treatment, the patient has been alive without local recurrence or distant metastasis.