Patient characteristics of olfactory neuroblastoma: experience from a tertiary cancer centre 2000-2016 covering Eastern Denmark.

The aim of this study was to report incidence and patient characteristics of olfactory neuroblastoma (ONB) at a tertiary cancer institution during a 16-year period. A retrospective review was conducted on patients with ONB treated at Rigshospitalet, Copenhagen from 2000 to 2016 covering Eastern Denmark. Patient demographics, symptoms, stage, pathology-reports, treatment, and outcome were extracted from the patient records and the Danish pathology register. The tumours were graded both histologically and clinically using Hyam's and Kadish classifications, respectively. We identified a total of 14 patients (ten males, four females, median age 57 years, range 17-81 years). Four patients were in Kadish stage A, one stage B, and seven stage C. According to Hyam's classification, two tumours were grade I, nine grade II, and three grade III. All patients were treated with surgery, eight in combination with radiotherapy, where one received proton therapy, and one a combination with chemotherapy. At a median follow-up time of 58 months, the 5-year overall survival was 90% (95% CI 61; 99). ONB is a rare disease; complete radical surgery alone or combined with radiotherapy offered good oncologic control and outcome. Long-term follow-up of ONB should be mandatory.