Clinical and Pathological Outcomes of Multilayer Resection of Olfactory Neuroblastomas via Endoscopic Endonasal Approach

Objective: To illustrate the utility of multilayer resection of olfactory neuroblastomas via endoscopic approach followed by radiation therapy.

Methods: A retrospective case series of 14 patients with olfactory neuroblastomas treated between 2008 and 2014 by a single surgeon using endoscopic endonasal techniques.

Results: Mean age of patients at presentation was 51.9 years. Three patients were females and 11 patients were male. Kadish staging at presentation was: A – 1 patient, B – 4 patients and C – 9 patients. Dulguerov stage at presentation was: T1 – 2 patients, T2 – 9 patients, T3 – 1 patient and T4 – 2 patients. The period of follow-up ranged from 12 months to 89 months. No post-operative complications were identified in all cases. Pathological margin studies revealed margin-free in 13 patients and margin-positive in 1 patient (Kaddish C, T2, Hymas II). In this margin-positive case, tumor invasion was found in the margin of the dura matter. No recurrence or metastasis was found. As for Hymas Grade, 1 patient showed Grade I and 13 patients showed Grade II.

Conclusions: Endoscopic endonasal surgery for olfactory neuroblastomas is a safe and efficacious technique. However, intraoperative margin study should be done carefully. Future studies are required to determine prognostic factors for recurrence and to develop adjuvant therapy.