Ectopic primary olfactory neuroblastoma of the nasopharynx: A case report and review of the literature

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.

Olfactory Neuroblastoma Managed with Endoscopic Sinus Surgery

Olfactory neuroblastoma (ONB) or esthesioneuroblastoma is a rare malignancy of the nose and paranasal sinuses that originates from the upper nasal vault. We report a rare case of ONB in a 27-year-old female patient with a 2-year history of nasal obstruction, sneezing, nasal discharge, and left eye protrusion. The patient was successfully treated with endoscopic sinus surgery and adjuvant radiotherapy (RT) with 5-year follow-up duration. Studying ONB cases is of great importance due to its rare occurrence, and the lack of literature regarding its management often creates a dilemma leading to nonstandardized treatment methods. Prolonged surveillance is essential due to its late recurrence and endoscopic resection followed by adjuvant RT, which may be a feasible and effective treatment. There is no single case of ONB published yet in Saudi Arabia, and to our knowledge, this is the first case report.

Mixed olfactory neuroblastoma and neuroendocrine carcinoma: An unusual case report and literature review

Background:

The aim of the study was to present a case of mixed olfactory neuroblastoma (ONB) and carcinoma, an extremely rare tumor with only a few cases in the published literature.

Case Description:

An otherwise healthy 27-year-old male presented with sinus complaints, headache, and unilateral eye discharge. Imaging and endoscopy revealed a mass presumed to represent a juvenile nasopharyngeal angiofibroma. Unexpectedly, the final pathology report revealed high grade mixed ONB and carcinoma. This tumor is the sixth and youngest documented patient with mixed ONB and carcinoma.

Conclusion:

Physicians should remain vigilant for the possibility of malignancy in their approach to nasal cavity masses, even in young otherwise healthy patients. Careful review of the immunohistopathology should also be taken, as mixed olfactory tumors such as these are aggressive, rare entities that require multidisciplinary oncologic care.