A rare case of primary Ewing's sarcoma presenting in the posterior nasal cavity with extension into the sphenoid sinus and a review of the literature

Ewing's sarcomas/primitive neuroectodermal tumors (PNET) are a group of tumors characterized by small round cells that rarely affect the bone and soft tissues of the nasal cavities. Herein, we describe the case of a 38-year-old man who presented with a one-year history of epistaxis, headache, hyposmia, anosmia, night sweats, weight loss, hearing loss, dysphagia, and nasal blockage. A computed tomography (CT) scan and magnetic resonance imaging (MRI) studies revealed a lesion in the posterior nasal cavities with extension into the sphenoid and ethmoid sinuses. Histological examination of a biopsied specimen obtained via flexible fiberoptic endoscopy showed small dark round cells with scanty cytoplasm arranged in solid nests and pseudorosette formations. The diagnosis of Ewing's sarcoma was confirmed by the positive reactive pattern of the neoplastic cells for CD99 by immunohistochemistry studies and also identification of a chromosomal translocation of FLI1 in PCR studies. Cervical lymph nodes and bone marrow involvement were also observed. The patient was treated by adjuvant chemotherapy including vincristine, endoxan, and adriamycin for 6 cycles followed by radiotherapy (eleven courses). Unfortunately, before completion of treatment, the patient died due to disease progression and brain metastasis.