Diagnosis: Multifocal nodular oncocytic hyperplasia (MNOH)
Oncocytic tumors of the salivary glands are extremely rare, representing fewer than 1% of all salivary gland tumors.1- 2 Oncocytes are transformed epithelial cells that arise from glandular and secretory epithelia.3 They are characterized by large size and eosinophilic, abundant, granular cytoplasm, typically because of increased numbers of mitochondria.3- 4 Oncocytic tumors are found in many different organs, including the kidneys, breasts, thyroid glands, upper respiratory tract, and lacrimal glands.3,5 They also exist in normal salivary gland tissue and occur in small aggregation among normal ductal and acinar cells.5 In some pathologic conditions of the salivary glands, however, oncocytes become the principal component.