In presentations of anosmia or dysosmia, magnetic resonance imaging may be required to screen for intracranial pathology such as olfactory neuroblastomas and other intracranial masses impacting on the olfactory pathway. This study aimed to establish positive magnetic resonance imaging findings of anosmia or dysosmia for scans performed before the coronavirus disease 2019 pandemic.

The study examined the outcome of patients who presented with isolated olfactory dysfunction and who underwent magnetic resonance imaging between 2015 and 2019.

Of the 131 patients, 41 (31.3 per cent) had normal scan findings, 50 (38.2 per cent) had insignificant paranasal mucosal disease and 6 (4.6 per cent) had mucosal thickening significant enough to require additional intervention. These interventions included repeat nasoendoscopy or commencement of intranasal or oral steroids. No patients had olfactory neuroblastoma.

Only 4.6 per cent of the magnetic resonance imaging scans revealed abnormal findings related to anosmia or dysosmia, and none required ENT surgical intervention. None of the magnetic resonance imaging scans identified an olfactory neuroblastoma or intracranial masses impacting on the olfactory pathway.

Olfactory neuroblastoma is a rare sinonasal malignancy, with poorly defined treatment protocols. Management at a tertiary centre was retrospectively evaluated to inform future treatment and follow up.

Cases treated with curative intent (2000–2014) were included. Data were collected, and overall and disease-free survival rates were calculated.

Eleven cases were identified, with a median follow up of 87 months. One patient was Kadish stage A, one was stage B, eight were stage C and one was stage D. The latter patient underwent chemoradiotherapy alone. The remaining patients proceeded to: endoscopic-assisted wide local excision (n = 2), anterior craniofacial resection (n = 4) or endoscopic craniofacial resection (n = 4). No patients had primary nodal disease or elective neck treatment. One patient had neoadjuvant chemoradiation. Six patients had post-operative radiotherapy; three received adjuvant chemotherapy. Two patients had late cervical node failure, and proceeded to neck dissection and post-operative radiotherapy. Two patients had late local recurrence. Ten-year overall and disease-free survival rates were 68.2 and 46.7 per cent, respectively.

Longer-term follow up is supported given the incidence of late regional and local recurrence. Prophylactic treatment of cervical nodes in locally advanced disease is an area for further investigation.