Endoscopic Resection of Esthesioneuroblastoma

Abstract

Esthesioneuroblastoma (olfactory neuroblastoma) is a rare malignant neoplasm originating from neuroepithelial cells. Treatment for this tumor has traditionally required a craniofacial resection through an external approach. The safety and efficacy of transnasal endoscopic resection is unknown. A series of five patients with Kadish stage A or B lesions of the anterior skull base were resected and immediately reconstructed endoscopically over a nine-year period. There were 2 males and 3 females with a mean age of 64 years. Three patients were treated primarily and two were treated secondarily for recurrences after failing a traditional external craniofacial resection and postoperative radiotherapy. All primary lesions received adjuvant radiotherapy. The mean follow-up time was 31 months. All patients were discharged within 4 days or less. Operative complications included temporary postoperative infraorbital anesthesia (1 patient), unplanned cerebrospinal fluid leak (1 patient), and an orbital hematoma (1 patient). None of these complications resulted in any permanent sequelae. Two patients had prolonged nasal crusting for up to one year due to a variety of factors; large cavities, radiation therapy, and exposed lyophilized dural graft. However, all skull base defects healed without any short- or long-term sequelae. There have been no local recurrences. Two patients (1 primary and 1 secondary) developed regional metastasis to the orbit or cervical lymph nodes managed with primary transorbital excision or modified neck dissection, respectively. All but one patient remain free of disease by clinical, endoscopic, and radiographic (CT or MRI) surveillance. The remaining patient recurred distally as an undifferentiated carcinoma in his temporal bone and lungs 12 months after the initial resection. In experienced hands select cases of esthesioneuroblastoma can be safely excised and reconstructed endoscopically with comparable degrees of tissue removal as with external approaches. Short-term oncologic results in this small series of patients appear to be comparable to traditional methods. Longer follow-up on a larger series of patients is warranted.