Bilateral Synchronous Ectopic Ethmoid Sinus Olfactory Neuroblastoma: A Case Report

Abstract

Background: Olfactory neuroblastoma (ONB), also known as esthesioneuroblastoma, is a rare malignant head and neck cancer thought to originate from the olfactory epithelium. It typically invades contiguous structures at presentation. We report a very rare case of multifocal and ectopic ONB.

Case report: A 41-year-old man presented with left nasal obstruction and occasional left epistaxis associated with headache. Endoscopic examination of the nasal cavities and computed tomography suggested bilateral polypoid masses. Histopathological diagnosis after endoscopic resection established bilateral olfactory neuroblastoma of the ethmoid sinuses. The patient received postoperative radiotherapy. He remains free of disease 4 years after treatment.

Conclusions: To the best of our knowledge this is the second documented case of multifocal ectopic olfactory neuroblastoma. Clinicians should consider ONB in the differential diagnosis of bilateral synchronous nasal and paranasal masses to avoid delayed diagnosis. Endoscopic resection of ONB could be an option in selected cases.

Figure 1.

Coronal computed tomography (CT) image revealing bilateral nasal masses with partial extension into the left maxillary sinus and partial opacification of the ethmoidal cells of the same side, as well as complete opacification of the right ethmoid and maxillary sinuses. The cribriform plate, the orbit walls, and the nasal septum seem to be uninvolved.

Figure 2.

Microscopic image of the typical lobular growth pattern of ONB. Hematoxylin – eosin staining, original magnification ×4.

Figure 3.

Microscopic image showing the uniform-appearing round cells surrounded by neurofibrillary material. Hematoxylin – eosin staining, original magnification ×40.

Figure 4.

Axial PET-CT images taken 1.5 months after endoscopic resection, showing no local or distant pathological uptake. The images are cut through the maxillary antrostomies.