Isolated primary maxillary sinus esthesioneuroblastoma presenting as idiopathic syndrome of inappropriate antidiuretic hormone

An adolescent girl with syndrome of inappropriate antidiuretic hormone secretion preceding the diagnosis of olfactory neuroblastoma - a case report

Objectives

We present an adolescent in whom olfactory neuroblastoma (ONB) was detected on follow-up magnetic resonance imaging (MRI) 2.5 years after SIADH diagnosis. Our case contrasts prior pediatric reports in which ONB and SIADH were diagnosed concurrently.

Case presentation

A previously healthy 13-year-old girl was found to have SIADH during evaluation for restrictive eating. Work-up ruled out adrenal, thyroid and paraneoplastic causes, diuretic use, and vasopressin receptor and aquaporin channel mutations. Brain MRI was normal except for paranasal sinus (PNS) inflammatory changes to the left fronto-maxillary sinuses and frontoethmoidal recess. The sodium levels normalized with fluid restriction (800-900 ml/m2/day). Multiple repeated attempts to liberalize fluid intake resulted in recurrent hyponatremia. Follow-up brain MRIs 4 and 11 months after the initial presentation showed persistent PNS inflammatory changes. A subsequent brain MRI 31 months after initial presentation demonstrated a lesion in the left frontoethmoidal recess extending into the left nasal cavity and biopsy showed low grade ONB. The patient underwent surgery with normalization of serum sodium on liberalized fluid intake. Seven days after surgery, she had recurrence of SIADH, and brain MRI showed remnant of the ONB at the fovea ethmoidalis. She completed adjuvant radiotherapy though her SIADH persisted.

Conclusions

Our case highlights the importance of considering ONB in the evaluation of children with SIADH. Idiopathic SIADH is rare in children and if no cause is identified, computed tomography of sinuses and nasal endoscopy should be considered earlier in the work-up of these patients, particularly in the absence of sinus symptoms.

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.

The syndrome of inappropriate antidiuretic hormone associated with nasal and paranasal malignant tumors

PURPOSE

To investigate the clinical characteristics of the syndrome of inappropriate antidiuretic hormone (SIADH) associated with nasal and paranasal malignant tumors.

METHODS

Patients with locally advanced or recurrence/metastatic malignant tumors of the nasal and paranasal sinuses were included. The SIADH was diagnosed according to the diagnostic criteria. The clinical characteristics of SIADH patients were retrospectively analyzed.

RESULTS

Six patients (6/188, 3.2%) met the diagnostic criteria of SIADH, including four olfactory neuroblastoma (4/26, 15.4%), one neuroendocrine carcinoma (1/9, 11.1%), and one squamous cell carcinoma (1/63, 1.6%). Five patients (83.3%) had severe hyponatremia; however, the hyponatremia could be improved by fluid restriction or tolvaptan. Three patients' SIADH were recovered during the chemotherapy and the other three were recovered after the surgery.

CONCLUSION

The incidence of SIADH associated with nasal and paranasal malignant tumors is relatively more common in olfactory neuroblastoma and neuroendocrine carcinoma. The hyponatremia caused by SIADH may be corrected by fluid restriction or tolvaptan, and the SIADH may be recovered through anti-tumor therapy.

Functional Olfactory Neuroblastoma Inducing Symptomatic SIADH

Olfactory neuroblastoma (ONB) is a rare malignancy of the sinonasal cavity, originating from neuroepithelial olfactory cells. Olfactory neuroblastoma can be difficult to diagnose due to its anatomic position and variable symptomatic presentation, leading to diagnosis at a more advanced stage. Here, we present the case of a 35-year-old man with no previous medical history who had a bicycle accident secondary to syncope. He was found to be hyponatremic and suspected to have syndrome of inappropriate antidiuretic hormone secretion (SIADH). In the workup of SIADH, a brain magnetic resonance imaging revealed a mass in the left middle meatus. The lesion secreted inappropriate amounts of ADH, resulting in symptomatic paraneoplastic SIADH. This ultimately led to the early recognition and successful resection of this rare ONB. The patient has remained disease-free for over 5 years. This case is a fortunate example of a functional malignancy of the sinonasal tract that was discovered early and successfully treated as a result of symptomatic SIADH.

Syndrome of Inappropriate Antidiuretic Hormone Release Secondary to Ectopic Olfactory Neuroblastoma: Case Report and Review of Literature

Ectopic olfactory neuroblastoma (ONB) is a rare neuroendocrine sinonasal malignancy which arises from sinonasal regions where olfactory neuroepithelium does not exist. Presentation of syndrome of inappropriate antidiuretic hormone release (SIADH) in patients with ectopic ONB is extremely rare. We report a case of a 22-year-old patient with ectopic ONB and paraneoplastic SIADH that was managed at our center. The ONB was arising from the left lamina papyracea and extending into the maxillary and ethmoid sinuses and filling the nasal cavity. Correction of sodium levels occurred within 24 hours of endoscopic resection via a combined trans-nasal transorbital approach. To avoid negative sequela secondary to rapid sodium correction, the patient was managed by desmopressin to obtain gradual sodium correction, which was achieved on the fourth postoperative day. Ectopic presentation of ONB with paraneoplastic SIADH is extremely rare with only 7 cases reported in the literature to date. Management via surgical resection and/or radiotherapy for these patients requires the managing clinician to be vigilant of serum sodium levels. A multidisciplinary approach is essential for optimal outcomes.

Syndrome of inappropriate antidiuretic hormone secretion after functional endoscopic sinus surgery

Functional endoscopic sinus surgery (FESS) is effective in cases of sinusitis where pharmacological treatment has not been successful. Patients undergoing FESS have reported an 85% improvement in symptoms as measured by the quality of life scores. Despite its convincing therapeutic benefit, complications sometimes occur with potentially dire consequences. We report the case of a 69-year-old patient who underwent FESS for recurrent frontal sinusitis and developed a syndrome of inappropriate antidiuretic hormone secretion (SIADH) on Day 3 post-operatively. To our knowledge, this is the first documented case of SIADH arising after an endoscopic intervention for frontal sinusitis.

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.

Esthesioneuroblastoma in children, adolescents and young adults

The esthesioneuroblastoma (ENB) is characterized as a rare malignant sinonasal tumor of neuroectodermal origin. Its starting point is the olfactory epithelium located in the upper part of the nasal cavities. Different nomenclatures have been proposed, but the most common are "esthesioneuroblastoma" and "olfactory neuroblastoma". ENBs have a bimodal distribution and mainly occur in teenagers, young adults and people aged 50-60. It is a very rare tumor in pediatrics since only around 100 cases have been reported so far. Within ENBs, we can distinguish tumors with different biological behavior ranging from localized forms with slow evolution to aggressive and metastatic forms at onset. In addition, precisely diagnosing undifferentiated tumors and distinguishing them from other etiologies of sinonasal tumors are sometime difficult. Added to its very low incidence, these characteristics make the study of ENB complicated. The standard treatment currently includes broad surgery followed by radiation therapy in localized resectable tumors. Neoadjuvant chemotherapy is indicated in large unresectable tumors and in metastatic forms. However, in certain indications, such as high-grade operable tumors, the role of perioperative chemotherapy remains to be defined. The objective of this analysis is to detail current knowledge regarding ENBs' epidemiological, biological, clinical and radiological characteristics as well as how to manage ENB in young patients.