Oncocytic Hyperplasia of the Parotid Gland: A Report of a Rare Case

Oncocytic hyperplasia of the parotid gland is a rare, benign condition marked by the proliferation of mitochondria-rich oncocytes, often mimicking neoplasms like pleomorphic adenoma. Its etiology remains unclear but may involve inflammatory triggers, as suggested by an associated granulomatous reaction in this case, possibly linked to prior COVID-19 infection. The condition is exceptionally rare, with limited data on prevalence. Patients typically present with painless parotid swelling, as seen in our 45-year-old male patient, initially suspected to have pleomorphic adenoma based on ultrasound, cytology (Milan category IV A), and contrast-enhanced CT findings. Definitive diagnosis relies on histopathology, which in this case revealed nodular oncocytic hyperplasia with a foreign body granulomatous reaction. Treatment involves surgical excision, such as superficial parotidectomy, to confirm diagnosis and rule out malignancy. This case underscores the diagnostic challenges of oncocytic hyperplasia and highlights the importance of histopathological evaluation to differentiate it from other salivary gland lesions, warranting vigilant monitoring due to its potential, though rare, progression to malignancy.