Hyperostotic esthesioneuroblastoma: rare variant and fibrous dysplasia mimicker

Abstract

A 65-year-old male presented with a 3-year history of orbital symptoms. An imaging-based diagnosis of fibrous dysplasia involving the skull base was made at another institution. CT showed a diffuse sinonasal mass and ground-glass appearance of the bones of the anterior skull base with bony defects and mucocele formation. MRI demonstrated an accompanying intracranial and orbital rind of soft tissue mass along the hyperostotic bones. FDG-PET showed corresponding intense hypermetabolism. Small cysts were observed at the tumor-brain interface. Biopsy revealed esthesioneuroblastoma with bone infiltration that is compatible with the hyperostotic variant of esthesioneuroblastoma. There are a few cases of hyperostotic esthesioneuroblastoma reported in the literature.

Keywords: Esthesioneuroblastoma; Fibrous dysplasia; Hyperostosis.

Fig. 1

Hyperostotic esthesioneuroblastoma in 65-year-old male mimicking fibrous dysplasia. A, B. Axial and coronal CT images show diffuse sclerotic expansile bones of anterior skull base and superior sinonasal cavity (arrows). Hyperostotic bones show homogeneous, ground glass appearance. C, D. Axial T2 and post-contrast T1 fat saturated MR images show enhancing rind of soft tissue mass (curved arrows) along hyperostotic bones (dashed arrows) which shows mild heterogeneous enhancement. Note formation of small cysts at tumor-brain interface (short arrows). Note formation of mucocele (long arrow). E, F. Axial and coronal FDG-PET CT fused color images show intense FDG avidity in hyperostotic bones (blue arrows) indicating diffuse tumor infiltration. Uptake in thin rind of soft tissue mass could not be separately visualized. G, H. Histologic images (H&E stains with 200 × (G) and 400 × (H) magnification). (G) Shows predominantly reactive bone formation, and (H) demonstrates sheet of tumor cells (arrows) within reactive bone.