Olfactory Neuroblastoma

Abstract

Few neoplasms are unique to the sinonasal tract, but sinonasal undifferentiated carcinoma and olfactory neuroblastoma are malignant tumors which require unique management. Due to the rarity of these tumors, practicing pathologists are not always aware of their distinctive clinical, radiographic, histologic, immunohistochemical, and molecular features. These cases are frequently submitted for consultation, further suggesting the diagnostic difficulties inherent to these tumors. Specifically, olfactory neuroblastoma is a neoplasm that can histologically mimic many tumors within the sinonasal tract, making recognition of this tumor important, as the management frequently requires a bicranial-facial surgical approach, a trephination procedure which can be quite technically difficult and challenging to achieve a good result. The management is therefore quite unique in comparison to other sinonasal tract malignancies, setting it apart diagnostically and managerially from other lesions.

Ectopic Sphenoid Sinus Pituitary Adenoma (ESSPA) with Normal Anterior Pituitary Gland: A Clinicopathologic and Immunophenotypic Study of 32 Cases with a Comprehensive Review of the English Literature

“…When keratin is reactive, it is limited to isolated cells and is not in a dot-like distribution. The specific anatomic site, lobular architecture, and unique immunohistochemical profile should allow for an accurate separation [55][56][57][58]. The distinction from ESSPA is important, since the management for ONB may involve major, destructive bi-craniofacial surgery (trephination) and possible additional potentially toxic radiotherapy and/ or chemotherapy, with a very different prognosis.…”

Olfactory Neuroblastoma: A Case Report

“…ONB represents approximately 2-3 % of all sinonasal tumors with an incidence of approximately 0.4 cases per million [3]. These tumors arise almost exclusively from the highly specialized sensory olfactory neuroepithelium normally encountered within the superior nasal vault, including the superior nasal concha, superior septum, roof of nose, and the cribriform plate of ethmoid [3,4]. ONBs may occur at any age; however, a bimodal age distribution with increased occurrences in the 2nd and 6th decades is commonly accepted.…”

“…ONBs may occur at any age; however, a bimodal age distribution with increased occurrences in the 2nd and 6th decades is commonly accepted. There is no definitive gender or racial predilection [4,5]. Typically, these are slow growing tumors with long-standing symptomology, often resulting in delayed biopsy and definitive diagnosis.…”

“…Extension into the adjacent paranasal sinuses, orbits and cranial vault is often seen. The radiographic findings may include the presence of a highly characteristic ''dumbbell-shaped'' occupying the superior nasal cavity and ethmoid sinus, extending through the cribriform plate and into the anterior cranial fossa with the ''waist'' at the level of cribriform plate [4,6]. CT scans are useful in determining bone erosion of the lamina papyracea, cribriform plate, and fovea ethmoidalis.…”

“…Contrast enhanced CT will demonstrate a homogeneously enhancing mass, while non-enhanced zones may suggest regions of necrosis. The extent and delineation of tumor is best determined by MRI with and without contrast, with T1-weighted images showing marked enhancement after gadolinium injection [4,7].…”