Low-grade fibromyxoid sarcoma involving the mandible: A diagnostic dilemma

Low-grade fibromyxoid sarcoma (LGFMS) is a distinctive variant of fibrosarcoma with a high metastasizing potential and is characterized by a long interval between tumor presentation and metastasis. LGFMS involving the maxillofacial region is a very rare entity with only six cases reported till date. LGFMS is characterized by its benign histological appearance, with spindle cells in whorling pattern, and collagenized and myxoid areas. The heterogeneous histological appearance makes the diagnosis challenging. Immunohistochemical staining has been reported by a number of authors, with some conflicting results, showing positivity with vimentin, but no immunoreactivity with antibodies to keratin, desmin, actin, S100 or epithelial membrane antigen. We present a case of a 35-year-old male patient who developed a mass on the left mandibular body region. The tumor was excised along with mental nerve at the level of the mental foramen. The tumor on pathologic and immunohistochemical evaluation was diagnosed as LGFMS.