Maxillary Sinus Myxofibrosarcoma Mimicking Nodular Fasciitis: A Rare Case Report.

Myxofibrosarcoma (MFS) is a fibroblastic soft tissue sarcoma that is extremely rare in the maxillofacial region. Due to its non-specific clinicoradiographic findings and challenging histopathological features, the diagnosis is difficult. Here, we present a case of MFS which was first diagnosed as nodular fasciitis. The initial examination of the incisional biopsy showed a benign-appearing proliferation of fibroblasts without features of malignancy. The patient returned with recurrence four months after surgical excision of the primary lesion. The second histologic study revealed a high-grade spindle cell sarcoma with myxoid features most compatible with MFS. Definitive diagnosis of MFS was confirmed by these histopathologic features and supportive immunohistochemical stains. Unfortunately, the patient died of disease 3 months later.