Oncocytoma Presenting as a Fat-Containing Intraparotid Mass

Abstract

An 87-year-old woman with a history of breast cancer status post lumpectomy presented with a lump under her left ear, which she noticed 3 months prior while applying skin cream. She was asymptomatic and initially deferred further workup. Upon developing transient ischemic attack symptoms, she underwent a head computed tomography (CT; Figure 1) at an outside facility which demonstrated enlargement of the superficial and deep lobes of the left parotid gland, with mixed soft tissue and fat attenuation. Physical examination revealed left-sided parotid fullness without discrete borders to it. There was no cervical adenopathy. Magnetic resonance imaging (MRI) demonstrated extensive, heterogenous T1 hyperintensity (Figure 2). There was suppression of these corresponding regions on fat-saturated T2 imaging and post-gadolinium imaging. The soft tissue components enhance with gadolinium relative to normal parotid parenchyma. The mass demonstrated diffusion restriction. Fine needle aspiration was performed and demonstrated groups of oncocytic cells.