Hyperostotic Esthesioneuroblastoma: Rare Variant and Fibrous Dysplasia Mimicker
A 65-year-old male initially presented at another institution with mild visual disturbances, loss of taste, and proptosis. CT imaging was suggestive of fibrous dysplasia. No treatment was administered at that time. Serial imaging performed over three years showed slow progression of the lesion? with no significant clinical deterioration. The patient was subsequently referred to our institution. CT, MRI and FDG-PET imaging were performed. CT () showed expansile, diffuse hyperostosis of the ethmoid bones, nasal septum, superomedial orbital walls and anterior frontal skull base. There was an extensive intracranial and extracranial enhancing soft tissue thickening along the hyperostotic bones. MRI () showed hypointense T1 and T2 signals of the bone marrow that corresponded to the hyperostotic bones on CT, with moderate diffuse enhancement. The rind of soft tissue mass along the hyperostotic bones showed hypointense to isointense T1 and T2 signals and diffuse enhancement. Intracranial rim enhancing small cysts were observed at the tumor-brain interface. Multi-focal extracranial mucoceles were also identified. FDG-PET () showed a corresponding diffuse hypermetabolic uptake in the soft tissues and bones. Endoscopic biopsies of the mass and bone confirmed the diagnosis of ONB with osseous tumor infiltration (). The patient opted for non-surgical treatment and expired in about 2 years.