Staging of Sinonasal and Ventral Skull Base Malignancies Dipan D. Desai, BS a , Bryan M. Brandon, MD a , Elizabeth L. Perkins, MD a , Charles S. Ebert, MD, MPH a , Adam M. Zanation, MD a,b , Brian D. Thorp, MD a, * INTRODUCTION Paranasal sinus and skull base malignancies include a heterogeneous group of tumors with widely varying histology and prognosis. Because of typically late presentation and the frequent involvement of critical structures, including the orbit and brain, these tumors represent a great challenge for head and neck surgeons and oncologists. Perhaps adding to this complexity is that paranasal sinus malignancies remain an uncommon and rare entity in Western countries. The incidence of these cancers is estimated to be less than 1 per 100,000 individuals per year, and they represent Conflict of Interest Statement: There are no conflicts of interest in the production of this article. a Department of Otolaryngology/Head and Neck Surgery, 170 Manning Drive, CB 7070, Chapel Hill, NC 27599, USA; b Department of Neurosurgery, 170 Manning Drive, CB 7060, Chapel Hill, NC 27599, USA * Corresponding author. E-mail address: brian_thorp@med.unc.edu KEYWORDS  Paranasal sinus malignancy  Cancer staging  Skull base  Head and neck cancer KEY POINTS  Sinonasal and skull base malignancies typically present at a late stage and have poor overall prognosis.  This understudied group of tumors includes an incredibly diverse set of pathologies with varying characteristics and etiologies.  The American Joint Committee on Cancer has established a common staging system for all sinonasal malignancies.  Many staging systems exist for a specific pathology and often have established prog- nostic value.  Thorough evaluation and imaging, and an awareness of certain characteristic tumor pat- terns of spread, are keys to accurate staging and guide optimal treatment. Otolaryngol Clin N Am 50 (2017) 257–271 http://dx.doi.org/10.1016/j.otc.2016.12.004 oto.theclinics.com 0030-6665/17/ª 2016 Elsevier Inc. All rights reserved.