18FDG uptake in sinonasal inverted papilloma detected by positron emission tomography/computed tomography

Inverted papilloma (IP) is a benign but locally aggressive sinonasal tumour. Aggressive surgical treatment has thus been traditionally recommended because of the risk of transformation in squamous carcinoma. CT and MRI are used to evaluate bone destruction and soft-tissue extension before surgery but may be ineffective to differentiate an inverted papilloma from squamous cell carcinoma. In recent years, F-18 Fluorodeoxyglucose positron emission tomography ((18)FDG-PET) is widely used as diffuse imaging procedure for diagnosis and followup of malignancy affecting the head and neck district. To evaluate the utility of (18)FDG-PET/CT in the diagnosis of patients with suspicious lesions for IP, twelve patients with suspicious sinonasal inverted papilloma were selected for this study. (18)FDG-PET/CT imaging was performed, and standard uptake value (SUV) was calculated for each patient. SUV(max) was considered as the maximum value measured in the visualized lesions. Seven of the twelve cases exhibited uptake of (18)FFDG with an SUV(max) ranging from 1 to 8.1. Histopathologic diagnosis after surgery confirmed the diagnosis of IP in five cases; all these cases had an SUV(max) > 3. The five cases, which exhibited absence of (18)FDG uptake, had a histological diagnosis of absence of IP.