Bilateral parotid oncocytoma with spontaneous intratumoral hemorrhage: a rare hypervascular parotid tumor with ASL perfusion.

We present a rare case of bilateral parotid oncocytoma with spontaneous intratumoral hemorrhage. Magnetic resonance imaging revealed multiple, bilateral, well-defined masses within the parotid glands with increased vascularity based on arterial spin labeling Magnetic Resonance (MR) perfusion imaging and restricted diffusion on diffusion-weighted imaging. During the clinical follow-up, the patient developed extensive hemorrhage from the largest tumor, presumably due to a combination of the hypervascular nature of oncocytoma and hemodialysis.