Management of olfactory neuroblastoma, neuroendocrine carcinoma, and sinonasal undifferentiated carcinoma involving the skullbase

Introduction: Sinonasal tumors that harbor neuroendocrine histologic features include olfactory neuroblastoma (previously known as esthesioneuroblastoma), sinonasal neuroendocrine carcinoma, and sinonasal undifferentiated carcinoma. These tumors represent a diverse spectrum of clinical behavior and as such require histology-specific management. Herein, we review the management of these sinonasal tumors with neuroendocrine features and discuss fundamentals of multi-modality care for each histology. An emphasis is placed on olfactory neuroblastomas, given their relative frequency and skullbase origin. Methods: A comprehensive literature review on contemporary management of olfactory neuroblastoma, sinonasal neuroendocrine carcinoma, and sinonasal undifferentiated carcinoma was performed. Results: Management of sinonasal tumors with neuroendocrine features can include surgical resection, radiation therapy, and/or chemotherapy. Due to their site of origin, these tumors can frequently involve the skullbase, which can require site-specific care. The optimal treatment modalities and the sequence in which they are performed are largely dependent on histology. In most cases, olfactory neuroblastoma is best managed with surgical resection followed by radiation therapy. Sinonasal neuroendocrine carcinomas represent a variety of histologic phenotypes (carcinoid, atypical carcinoid, small cell, and large cell), which determine the optimal treatment modality. Finally, sinonasal undifferentiated carcinoma is likely best managed by induction chemotherapy with subsequent therapy dictated by the initial response. Conclusions: A team approach to multi-modality care is essential in the treatment of olfactory neuroblastoma, sinonasal neuroendocrine carcinoma, and sinonasal undifferentiated carcinoma. Early biopsy, histologic diagnosis, and comprehensive imaging are critical to determining the appropriate management paradigm.