Both myxofibrosarcoma and undifferentiated pleomorphic sarcoma (UPS) are sarcomas that primarily occur in the extremities of older patients. UPS (previously known as malignant fibrous histiocytoma) is now considered a diagnosis of exclusion, representing a group of high-grade, heterogeneous tumors with no clear line differentiation and characterized by high rates of distant metastases. Myxofibrosarcoma (formerly myxoid variant of malignant fibrous histiocytoma) is a distinct histologic entity that is largely distinguished from UPS by its myxoid stroma and curvilinear vascular pattern. Myxofibrosarcoma tends to have a locally infiltrative behavior that can often be seen as T2 hyperintense “tails” on magnetic resonance imaging. Local recurrence rates can be as high as 61% and are independent of grade. Unlike other sarcomas, it is recommended that tumors be excised with at least a 2 cm margin around both clinically and radiographically evident tumor. Low-grade tumors do not tend to metastasize but can recur as high-grade tumors with increased metastatic potential. Surgery is the mainstay of treatment for localized disease. For high-grade tumors, this may require complex plastics and vascular reconstruction. Selecting cases for multimodality therapy, including radiation and chemotherapy, should be done on a case-by-case basis after review by a multidisciplinary sarcoma team with particular attention to a patient’s risk of local recurrence and distant metastases. Further studies into histology-specific therapeutic targets will help inform future clinical trials.
This review contains 4 figures, 4 tables and 54 references
Key words: chemotherapy, distant metastases, extremity sarcoma, local recurrence, malignant fibrous histiocytoma, myxofibrosarcoma, radiation, sarcoma, surgical margins, T2 hyperintense tails, undifferentiated pleomorphic sarcoma
Primary undifferentiated high-grade pleomorphic sarcoma/malignant fibrous histiocytoma arising from the mandible
