Clinical Implications of Incidental Sinonasal Positive FDG Uptake on PET-CT

Fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) has been increasingly used in the past decade. Incidental FDG-avid findings are encountered in these studies, several of which with clinical significance. However, the significance of incidental FDG-avid sinonasal findings has not been studied to date.Retrospective cohort study.A single tertiary medical center.The medical records were reviewed of patients with incidental sinonasal positive FDG uptake between 2007 and 2016 who referred for further otolaryngological diagnostic workup.A total of 26 patients were identified, all of whom underwent a diagnostic surgical procedure. Histopathology revealed chronic inflammation (n = 12, 46.1%), malignancy (n = 7, 26.9%), inverted papilloma (n = 4, 15.5%), and fungal infections (n = 3, 11.5%). A unilateral maxillary sinus with FDG uptake was documented for 16 (61.5%) patients. CT evidence of bilateral disease and mucosal or sinus wall thickening correlated with inflammatory disease.Incidental lesions with positive FDG uptake in the sinonasal cavities are at a high risk (40%) of being neoplastic. A diagnostic biopsy is advocated in these cases.