Olfactory neuroblastoma presenting with exclusive orbital manifestations

We report a case of an olfactory neuroblastoma revealed by atypical presentation with only ophthalmic symptoms. A 73-year-old woman presented with exophthalmos, left chemosis, decreased visual acuity, and diplopia. CT scan revealed a heterogeneous mass with isolated maxillary sinus, orbital floor, and lower eyelid invasion. This orbital lesion has no major ethmoidal extension (a single anterior ethmoidal cell appears retrospectively invaded). The biopsy sample of the hardened tumefaction revealed after histological examination an olfactory neuroblastoma (or esthesioneuroblastoma). The patient was treated by surgery (resection of the lesion and neck dissection) followed by postoperative irradiation.Olfactory neuroblastoma has no specific symptoms, but habitually presents as an ethmoidal lesion possibly accompanied with ophthalmic manifestations (in 20% to 30% of cases) due to orbital extension. This type of unusual presentation requires our attention, and we discuss the actual knowledge about the pathogenesis, clinical presentation, and treatment of this rare entity.