Growth rate characteristics of Warthin's tumours of the parotid gland.

The aim of this study was to evaluate growth characteristics of parotid gland Warthin's tumours. The medical records of 134 patients who had a cytological or histopathological diagnosis of Warthin's tumour between 1997 and 2013, at a single tertiary care centre, were reviewed retrospectively. Thirteen of these patients underwent observation with 30 serial computed tomography or magnetic resonance imaging scans of the head and neck, with 24 Warthin's lesions identified. The mean length of time between scans was 882 days, and mean initial and final sizes per lesion were 3.9 cm(3) and 5.6 cm(3), respectively. Average growth of these lesions was 8% per year (95% confidence interval -27% to 43%; range -148% to 460%; median -8%), and was highly variable (standard deviation 96%). Age over 75 years was associated with slower growth (P=0.03), but gender, smoking status, multifocality, bilaterality versus unilaterality, and initial size did not correlate with the growth rate. Warthin's tumours appear to have an approximate average doubling time of 9 years, but can have a wide range of growth rates, with many cases showing a reduction in size. Either conservative management or surgical resection could be supported by these data, depending on the current size of the tumour, appearance, symptoms, and the age, health, and wishes of the patient.