Although malignancies in the sinonasal cavity comprise only 3% of all head and neck cancers and 1% of all malignancies,1 they are important disease entities to consider because of their nonspecific clinical presentation. There is considerable overlap of symptoms of sinonasal tumors with symptoms of the much more common rhinosinusitis. CT for rhinosinusitis symptoms is common in clinical practice and often ordered by primary care physicians who do not have the instruments to perform thorough endoscopic nasal examinations. Thus, the first physician to suggest the presence of a sinonasal lesion often is the general radiologist, frequently one without neuroradiology subspecialty training. It is imperative that radiologists not only are aware of imaging findings of both benign and malignant sinonasal masses and mass-like lesions but also are able to recommend the next appropriate steps in patient management.