Solitary fibrous tumor of the mandible

Abstract

A 41-year-old woman presented with a facial asymmetry in the mental region and a painful, well-circumscribed, tender mass in the right lower buccal vestibule, associated with extensive ill-defined bone rarefaction with subtle cortical bone resorption. Microscopically, a proliferation of bland spindle cells interspersed with collagen fibers and prominent staghorn-like blood vessels was observed. Immunohistochemical analysis revealed strong positivity for CD34, Bcl-2, CD99, and STAT-6, confirming the diagnosis of Solitary Fibrous Tumor (SFT). Conservative surgical enucleation was performed, and 4 years later, recurrence was observed with extensive bone involvement and moth-eaten margins resembling a malignant tumor. SFT is a distinctive spindle cell tumor of fibroblastic differentiation, characterized by prominent branching staghorn-like vessels and a specific NAB2::STAT6 gene fusion. We herein contribute with a central SFT of the mandible with recurrent behavior and radiographic appearance suggesting malignancy.