Case reportAdvanced esthesioneuroblastoma with hyperostosis of the anterior skull base

Esthesioneuroblastoma, also known as olfactory neuroblastoma, is a rare type of neuroectodermal tumor arising from the superior portion of the nasal cavity, sometimes locally invading the anterior skull base. We report the case of a 44-year-old man having a 3-year history of nasal obstruction and anosmia, acute worsening of vision in his right eye, and facial numbness on the right side. Brain computed tomography and magnetic resonance imaging revealed an extensively enhanced soft tissue tumor involving bilateral nasal and orbital cavities, ethmoid sinuses, the floor of the anterior cranial fossa, and intradural invasion. In particular, prominent hyperostosis, a rare associated radiological finding, was observed on both sides of the orbital roofs. Bifrontobasal craniotomy involving a radical removal of the soft tissue mass, including the intradural extension, was performed; the bilateral hyperostosis of the orbital roofs was drilled off for decompression of the narrowed orbital cavities. Pathological reports confirmed esthesioneuroblastoma. The postoperative course was smooth, and the vision improved. The tumor did not recur for 1 year after postoperative radiotherapy and adjuvant chemotherapy.