Diffuse pseudotumorous oncocytosis of the parotid gland. A case report

: Pseudotumorous oncocytosis of the parotid gland is very uncommon and frequently misdiagnosed since it generally presents as a true tumor. The clinical presentation and imaging features of a 6-cm diameter left parotid mass led to the diagnosis of a tumor in a 73-year-old man. At pathology examination of the partial parotidectomy specimen the "tumor" was found to be a metaplastic oncocytic lesion. We discuss the diagnostic criteria, differential diagnosis, and etiopathogeny of this lesion.