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

Figure 2 Left parapharyngeal space nerve sheath tumour in a 35-year-old lady. A: Axial T2W FS image shows multiple intensely T2 hyperintense areas within suggestive of cystic degeneration (dashed arrow); B: Sagittal T2W image shows blood fluid level within the cystic areas (dashed arrow) along with thickened distal exiting nerve (solid arrow); C: Axial T1W FS post contrast image shows intense enhancement in solid areas of the mass while cystic areas are hypointense; D and E: DWI at b1000 (D) s/mm² and ADC map (E) show restricted diffusion in solid areas of the mass (dashed arrow) while cystic areas show free diffusion (solid arrows); F: Photomicrograph shows alternating hypercellular (Antoni A) and hypocellular (Antoni B) areas (H-E; original magnification: × 100). DWI: Diffusion weighted imaging; ADC: Apparent diffusion coefficient.