Sclerosing epithelioid fibrosarcoma of the jaw: a case report and literature review.

Introduction: Sclerosing epithelioid fibrosarcoma (SEF) is an extremely rare form of bone and soft tissue sarcoma. It occurs mainly in the deep soft tissue of the lower extremities, with few cases reported in the head and neck region. Tumors involving the oral and maxillofacial region (OMFR) and intraosseous examples are rare.

Case Presentation: We present a 52-year-old male with a radiolucent lesion at the apex of the left mandibular second molar tooth with the clinical impression of a periapical granuloma. The patient has a history of SEF of the skull, which was treated by chemotherapy and radiation. Histopathologic examination revealed islands of highly cellular, basophilic bone and osteoid surrounded by loose fibrous stroma, which contains large lobules and islands of round to oval cells with distinct cell borders and faintly granular eosinophilic cytoplasm. Tumor cells were strongly positive for MUC4 and INI-1. Based on these findings, a diagnosis of high-grade malignancy consistent with SEF was made, and correlation with the primary lesion was recommended.

Conclusion: SEF is a rare tumor seen in OMFR, and therefore, it should be included in the differential diagnosis of any high-grade malignancy. Immunohistochemical stain for MUC-4 evaluation is important for the diagnosis of SEF.