Fine Needle Aspiration Cytology and Diagnostic Pitfalls in Warthin's Tumor with Necrotizing Granulomatous Inflammation and Facial Nerve Paralysis: A Case Report

Warthin's tumor can be associated with various secondary changes that challenge both clinical and cytologic diagnosis. A 44-year-old man presented with a Warthin's tumor (WT) that was associated with multiple secondary changes. The right parotid mass was present and mostly asymptomatic for 6 years, but during the 7th year, there was pain and ipsilateral facial nerve dysfunction following abrupt increase in size of the mass. Fine needle aspiration (FNA) yielded murky, brown, viscous fluid, and the residual mass was also aspirated. Cytologic examination showed acute, chronic and granulomatous inflammation and rare squamous cells in a background of finely granular necrotic debris. Oncocytes were not identified. Histologic examination of the excised mass revealed a WT with extensive necrotizing granulomatous inflammation, with acute and chronic inflammation, fibrosis and squamous metaplasia. Microorganisms were not identified by culture or by special stains of the FNA cell block and histologic sections. The secondary changes observed in this case probably relate to spontaneous infarction of the WT. Awareness of the secondary changes that can occur in WT will help prevent misdiagnosis, which could result in inappropriate therapy, including unnecessary radical surgery.