Atypical Olfactory Neuroblastoma Presenting as Sinonasal Polyposis with Nasopharyngeal Extension: A Case Report

Background: Olfactory neuroblastoma also known as Esthesioneuroblastoma (ENB) is a tumor arising from the basal layer of olfactory epithelium in the superior recess of the nasal cavity in the region of cribriform plate. Incidence peaks once in 11 20 years of age and again in 50 60 years of age. It is equally found in men and women. Aim: The main aim of this case report is to characterize the clinical features of ENB showing nasopharyngeal involvement and its importance in the differential diagnosis of sinonasal neuroendocrine malignancies. Case presentation: Two cases are reported. The first case was a 21-year-old male with symptoms of nasal obstruction, recurrent epistaxis, nasal discharge, headache and paresthesia over the face with an evolution of 1 year with no previous history of trauma. Diagnostic nasal endoscopy revealed reddish gray mass filling bilateral nasal cavities. Posterior rhinoscopy revealed mass coming through choanae and filling the nasopharynx. Endoscopic resection of tumor was done and postoperatively all the symptoms of the patient resolved. The second case was a 62-year-old male with complaints of nasal obstruction, nasal discharge, recurrent epistaxis, anosmia and difficulty in swallowing. On computed tomography, anteriorly, the mass was extending up to external nares and posteriorly up to the nasopharynx, superiorly up to nasal roof and inferiorly up to hard palate. No obvious erosion of floor of anterior cranial fossa was seen. No intracranial extension was seen. Surgery was advised but patient refused to undergo any treatment. Conclusion: This study highlights the characteristics and clinical features of ENB showing nasopharyngeal involvement and their importance in the differential diagnosis of sinonasal neuroendocrine malignancies. Corresponding author. J. P. Purohit et al.