Gamma Knife® radiosurgery for recurrent intracranial olfactory neuroblastoma (esthesioneuroblastoma): a case report

BACKGROUND We report the use of salvage radiosurgery to manage an aggressive olfactory neuroblastoma (esthesioneuroblastoma) with multiple recurrences and intracranial extension. CASE PRESENTATION A 43-year-old Caucasian woman presented 11 years ago with progressive nasal blockage and headaches. A necrotic polyp originating in her left middle meatus and extending to the ethmoid air cells and cribriform plate (Kadish stage C) was radically resected via a craniofacial approach. Four years later, a local recurrence extending into her left cavernous sinus was identified and deemed inoperable. She received vincristine, ifosfamide, doxorubicin and etoposide chemotherapy (with minimal benefit) and external beam radiotherapy (60Gy in 30 fractions) to her skull base. Two years later, tumour extension in her left neck was treated with radical radiotherapy. She developed visual disturbances in her left eye, which progressed to blindness in the next two years. Having exhausted chemoradiotherapy, the left cavernous sinus esthesioneuroblastoma was treated with Gamma Knife® radiosurgery 2 years ago (20Gy at 50% isodose, tumour volume 7.5cm3). At one year, there was dramatic reduction in the tumour and no new symptoms; however, there were new tumour foci (in her left frontal lobe and above her right orbital apex). These were again treated with radiosurgery (20Gy at 50% isodose, total tumour volume 0.67cm3). Repeat imaging at six months showed no further disease progression. CONCLUSION Whilst rare, olfactory neuroblastoma (esthesioneuroblastoma) can present management challenges and Gamma Knife® radiosurgery may prove a useful strategy in controlling intracranial spread.