Masses, Malignancy, and Mimics: CT and MR Imaging of the Sinonasal Cavity

Although sinonasal malignancies are relatively rare entities, the frequency of sinus imaging ensures that most radiologists will encounter an unsuspected sinonasal neoplasm at some point in their career. Given that the initial clinical presentations are often nonspecific and may mimic inflammatory rhinosinusitis, it is essential that the practicing radiologist becomes familiar with the specific CT and MR imaging findings that should raise suspicion for an underlying neoplasm. In the course of this review, we highlight the imaging features of a spectrum of sinonasal neoplasms, both benign and malignant, with emphasis on the distinct and complementary roles of CT and MR imaging in the differentiation from common inflammatory disease. We also highlight key anatomic relationships crucial to identifying routes of disease spread with an eye toward disease staging and surgical management.Learning Objectives: To familiarize the practicing radiologist with the key imaging features that should raise suspicion for an underlying sinonasal malignancy and to understand the complementary roles of CT and MR imaging in evaluating routes of locoregional and perineural disease spread.