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

Objectives: 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. Study Design: Retrospective cohort study. Setting: A single tertiary medical center. Materials and Methods: The medical records were reviewed of patients with incidental sinonasal positive FDG uptake between 2007 and 2016 who referred for further otolaryngological diagnostic workup. Results: 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. Conclusions: 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.