Benign neck masses showing restricted diffusion: Is there a histological basis for discordant behavior?

Figure 1 Warthin’s tumour in right parotid gland in a 60-year-old man. A: Axial T2W FS image shows heterogeneous solid-cystic mass arising exophytically from right parotid gland with mildly hyperintense septae and mural nodules (dashed arrow) while cystic areas are hypointense (solid arrow); B and C: DWI at b1000 (B) s/mm² and ADC map (C) show restricted diffusion in septae and mural nodules of the mass; D: Photomicrograph shows a well encapsulated tumor comprising of acini with oncocytic change separated by sheets of lymphocytes (H-E; original magnification: × 100). DWI: Diffusion weighted imaging; ADC: Apparent diffusion coefficient.