Bilateral Synchronous Ectopic Ethmoid Sinus Olfactory Neuroblastoma: A Case Report

Olfactory Neuroblastoma Is Not Always Located at the Roof of the Nasal Cavity

Objectives

To evaluate the imaging characteristics of the tumor, emphasizing its location, and to determine the frequency of typical and atypical locations of olfactory neuroblastoma (ONB).

Materials and Methods

We retrospectively reviewed the computed tomography and magnetic resonance imaging findings of patients with pathologically proven ONB between April 2000 and April 2023. Demographic information, chief complaints, tumor location, and tumor extension were extracted.

Results

Of the 58 patients, 50 (86.2%) had the epicenter of the mass at the superior part of the nasal cavity, while eight patients (13.8%) had the epicenter at other atypical locations: seven patients (12.1%) at the middle part of the nasal cavity and one patient (1.7%) within both sphenoid sinuses.

Conclusion

ONB is not always present in the upper part or the roof of the nasal cavity, and a significant number of ONBs are occasionally found in the rest of the nasal cavity and other atypical locations.

Ectopic Olfactory Neuroblastoma: Systematic Review of a Rare Clinical Entity among Sinonasal Tumors

Objectives  Ectopic olfactory neuroblastoma is an uncommon manifestation of an already rare neoplasm. We aimed to systematically review the literature for cases of ectopic olfactory neuroblastoma to better characterize this rare disease entity and to present two new case reports. Methods  A search of the PubMed and Embase databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify English-language articles reporting cases of ectopic olfactory neuroblastoma, published from 1955 through November 2021. Results  Sixty-six cases of ectopic olfactory neuroblastoma were identified in 62 articles including the current review. Ectopic olfactory neuroblastoma arose in a wide age range (2-89 years) without significant sex predilection. It occurred most commonly in the ethmoid (25%), maxillary (25%), and sphenoid (16%) sinuses. Seventy-three percent of cases presented with low Hyams grade (I and II). The most common symptoms were nasal obstruction (32%) and epistaxis (32%). Paraneoplastic syndromes were observed in 27% of patients. The most common treatment was surgical resection followed by adjuvant radiotherapy. Overall, 76% of all patients were disease-free at the time of last follow-up. Locoregional recurrences and distant metastases were found in 19 and 5% of cases, respectively. Conclusion  This systematic review describes previously reported cases of ectopic olfactory neuroblastoma, a disease entity with poorly understood characteristics. Physicians should consider olfactory neuroblastoma in the differential diagnosis for sinonasal masses, as their ectopic presentation may present considerable diagnostic and therapeutic difficulties. Patients with olfactory neuroblastoma may benefit from long-term follow-up and routine endoscopic examinations for surveillance of ectopic recurrences.

Ectopic Primary Olfactory Neuroblastoma: Case Series and Literature Review

OBJECTIVE

Olfactory neuroblastoma (ONB) is a rare malignant tumor arising in the upper nasal cleft. Rarely, ONB may originate in ectopic sites and the impact of this on prognosis and treatment strategies continues to be debated.

METHODS

A retrospective analysis was undertaken of patients with ectopic ONB treated between 2000 and 2020 in a tertiary-care referral center for skull base tumors. Three patients were included in this analysis: a 37-year-old woman with ONB arising from the bulla ethmoidalis; a 28-year-old man with inappropriate secretion of antidiuretic hormone caused by a maxillary sinus ONB; and a 41-year-old man with lacrimal sac ONB. Preoperative workup, surgical approach, adjuvant treatments and postoperative surveillance were analyzed. Relevant literature published between 2000 and January 2021 was fully reviewed to investigate oncologic outcomes and delineate the standard of care for such rare tumors.

RESULTS

All patients were treated via endoscopic endonasal resection with radical intent, followed by adjuvant treatments when required. No recurrences of disease were observed after a mean follow-up time of 32 months (range, 12-60 months). Data emerging from the literature suggest that a multidisciplinary treatment approach, including free-margins surgical resection followed by adjuvant radiotherapy or radiochemotherapy, is recommended. Olfactory bulb and dura preservation should be attempted whenever feasible.

CONCLUSIONS

Endoscopic endonasal surgery should be preferred, when possible, to achieve complete excision to minimize patients' morbidity. The ectopic site of origin affects prognosis and should be considered when selecting the appropriate multimodal treatment strategy.

Intranasal Esthesioneuroblastoma: CT Patterns Aid in Preventing Routine Nasal Polypectomy

BACKGROUND AND PURPOSE

Esthesioneuroblastoma is a neuroectodermal tumor that commonly arises in the nasal cavity olfactory recess and, when isolated to the intranasal cavity, can be indistinguishable from benign processes. Because lesional aggressiveness requires a more invasive operation for resection than polypectomy, patients with isolated intranasal lesions were studied to define distinguishing CT characteristics.

MATERIALS AND METHODS

Patients with intranasal esthesioneuroblastoma and controls without esthesioneuroblastoma with olfactory recess involvement were identified by using a report search tool. Studies demonstrating skull base invasion and/or intracranial extension were excluded. The imaging spectrum of these lesions was reviewed on both CT and MR imaging, and CT findings were compared with those of controls without esthesioneuroblastoma. Two blinded readers assessed subjects with esthesioneuroblastomas and controls without esthesioneuroblastoma and, using only CT criteria, rated their level of suspicion for esthesioneuroblastoma in each case.

RESULTS

Eight histologically proved cases of intranasal esthesioneuroblastoma were reviewed. All cases had CT demonstrating 3 main findings: 1) an intranasal polypoid lesion with its epicenter in a unilateral olfactory recess, 2) causing asymmetric olfactory recess widening, and 3) extending to the cribriform plate. Twelve patients with non-esthesioneuroblastoma diseases involving the olfactory recess were used as controls. Using these 3 esthesioneuroblastoma CT criteria, 2 blinded readers evaluating patients with esthesioneuroblastoma and controls had good diagnostic accuracy (area under the curve = 0.85 for reader one, 0.81 for reader 2) for predicting esthesioneuroblastoma.

CONCLUSIONS

Esthesioneuroblastoma can present as a well-marginated intranasal lesion that unilaterally widens the olfactory recess. CT patterns can help predict esthesioneuroblastoma, potentially preventing multiple operations by instigating the correct initial operative management.