Hyperostotic esthesioneuroblastoma: CT and MR findings

Olfactory neuroblastoma is a malignant, slow growing, neurogenic tumor that originates in the olfactory mucosa of the upper nasal cavity. Its CT appearance, i.e., a soft tissue mass adherent to the cribriform plate usually with bone lysis, has been described. Two cases are presented in which this entity was associated with exuberant bony hyperostosis, a feature not previously reported. The differential diagnosis of nasoethmoid soft tissue masses with associated hyperostosis is reviewed.