Warthin’s Tumour as a Parotid Gland Incidentaloma Identified by PET–CT Scan in a Large Series of Cases

Occasionally in imaging scans there are findings unrelated to the pathology for which the scan was indicated, findings that are called incidentalomas. Warthin tumors have a high glucose avidity, being one of the common incidentalomas in PET–CT scans. The aim of the present study is to analyze the frequency of occurrence of Warthin’s tumor as an incidental finding in a large series of patients undergoing 18F-FDG PET–CT. Retrospective analysis of 18F-FDG PET–CT scans performed in our center during the period 2010–2021. Parotid hypermetabolic lesions were identified, as well as their SUVmax, size, smoking habit, BMI (body mass index), and otorhinolaryngology follow-up. 31,423 PET–CT-18FDG studies corresponding to 12,806 patients were analyzed. The frequency of incidentalomas at the parotid level with a diagnosis compatible with Warthin’s tumor was 0.87% (n = 111). Eighty percent of the patients with incidentalomas accordant to Warthin’s tumor had a history of tobacco use. The highest percentage of incidentalomas compatible with a Warthin tumor was found in patients in whom the indication for PET–CT was the study of a lung carcinoma (1.44%). Only 37% of patients with a PET–CT lesion compatible with a Warthin’s tumor were referred for evaluation by the Otorhinolaryngology service. The incidence of Warthin’s tumor in 18-FDG PET–CT scans in our center was 0.87%.