The incidence of Warthin tumours and pleomorphic adenomas in the parotid gland over a 25-year period

ObjectivesPleomorphic adenoma (PA) is reported to be the most common benign parotid tumour followed by Warthin tumour (WT), but the proportion of these two entities might have changed. DesignRetrospective file analysis. SettingTertiary referral head and neck centre. ParticipantsPatients who underwent a parotidectomy within a period of 25 years (1990-2014). Main outcome measuresRate of occurrence of PA and WT as well as the development of the PA/WT ratio over the years. ResultsOverall, 1818 patients with WT (707, 38.9%) and PA (1111, 61.1%) were identified. There was a dominance of PA over WT in all years. An increase in percentage of WT, from 24% in 1990 to 48% in 2014, in comparison with PA was evident. ConclusionsIn our single-institution hospital-based material of parotidectomies, the percentage of WT in comparison with PA has significantly increased over the last 25 years.