Ectopic primary olfactory neuroesthesioblastoma originating from the anterior nasal septum
Keywords:Olfactory neuroesthesioblastoma, Ectopic growth, Nasal septum
Olfactory neuroestesioblastoma (ONB) is a rare malignant neoplasm of the paranasal sinus. Ectopic growth of ONB outside the region of neuroepithelial cells are exceedingly rare and so far, it has only been reported to arise from the maxillary sinus, sphenoid sinus, posterior septum and the turbinates. None has been reported to originate from the anterior cartilaginous part of the septum. A 31-year-old lady, who was premorbidly well, presented with 2 episodes of spontaneous epistaxis from the left nostril in 1 year. The epistaxis worsened over the one week prior to her visit. Nasoendoscopy showed a vascularised round mass at the anterior part of the left septum. Initial biopsy was reported as possible ectopic squamous cell carcinoma of the salivary gland. A repeat biopsy then confirmed the diagnosis of ONB. Computed tomography scan of the paranasal sinus showed an isolated mass (18×18 mm) arising from the anterior part of the septum. Endoscopic resection of the tumour was done and histopathology report revealed as ONB. Post-operative radiotherapy was given with a total dose of 66. The rarity of ONB poses a challenge during diagnosis. The histological identification is difficult as these tumours may show little or no differentiation. A simple biopsy from the mass is often insufficient and may produce inaccurate results. Isolated growth without involvement of the upper nasal vault is extremely rare. A possible explanation would be the presence of ectopic neuroepithelial cells at the cartilaginous anterior septal area that has failed to degenerate during fetal development.
Vidya MN, Shivakumar S, Biswas S, Vijay Shankar S. Olfactory Neuroblastoma: Diagnostic Difficulty. Online J Health Allied Scs. 2010;9(4):18.
Cho KS, Lee DG, Choi KU, Roh HJ. Primary olfactory neuroblastoma originating from the posterior nasal septum. Otolaryngol Head Neck Surg. 2010;142:776-7.
Wenig BM. Undifferentiated Malignant Neoplasms of the Sinonasal Tract. Arch Pathol Lab Med. 2009;133(5):699-712.
Bourne TD, Bellizzi AM, Stelow EB, Loy AH, Levine PA, Wick MR, et al. p63 Expression in Olfactory Neuroblastoma and Other Small Cell Tumors of the Sinonasal Tract. Am J Clin Pathol. 2008;130(2):213-8.
Papacharalampous GX, Kotsis GP, Vlastarakos PV, Papadopoulou EP, Saravakos PK, Davilis DI. Olfactory Neuroblastoma Treated by Minimally Invasive Endoscopic Resection and Postoperative Adjuvant Radiotherapy: A Representative Case and an Updated Review of the Literature. J Cancer Ther. 2012:3(6):1074-9.