Which salivary gland tumor is characterized by the presence of oncocytes and is most commonly bilateral?

Explanation

## Warthin Tumor: Benign Salivary Neoplasm with Distinctive Features ### Overview Warthin tumor (papillary cystadenoma lymphomatosum) is a benign salivary gland tumor with a unique histologic composition and epidemiologic profile. ### Histopathology **Key Point:** Warthin tumor is characterized by a dual epithelial-lymphoid component: columnar epithelial cells (oncocytic) arranged in papillary patterns within a rich lymphoid stroma. ### Oncocytic Nature - Oncocytes are epithelial cells rich in mitochondria - Stain positive for phosphotungstic acid-hematoxylin (PTAH) - Appear granular and eosinophilic under light microscopy - Warthin tumor contains prominent oncocytic epithelium ### Epidemiologic Features | Feature | Warthin Tumor | |---|---| | **Bilaterality** | 5–15% bilateral (highest among benign salivary tumors) | | **Gender predominance** | Male (4:1 ratio) | | **Smoking association** | Strong (smoking increases risk) | | **Age of presentation** | 40–70 years | | **Most common site** | Parotid gland (90%) | | **Malignancy risk** | 0% (entirely benign) | **High-Yield:** Warthin tumor is the ONLY common salivary tumor with significant bilateral presentation (5–15%). If a patient presents with bilateral parotid masses, Warthin tumor should be high on the differential. ### Clinical Presentation - Slow-growing, painless parotid mass - May fluctuate in size - Superficial location within parotid - No facial nerve involvement ### Diagnosis - Fine needle aspiration cytology (FNAC): Oncocytes + lymphoid background - Imaging: Well-defined, cystic or mixed lesion **Clinical Pearl:** A middle-aged or elderly male smoker with a painless parotid mass (especially if bilateral) presenting with a history of fluctuating size is classic for Warthin tumor. ### Management - Observation if asymptomatic - Superficial parotidectomy if symptomatic or diagnostic uncertainty - Excellent prognosis; recurrence rare (<5%) **Mnemonic:** **WART** = **W**arthin, **A**ge 40–70, **R**ich lymphoid stroma, **T**wo-sided (bilateral potential).