A 52-year-old man presents with a painless, slow-growing swelling in the parotid region over 6 months. Imaging confirms a parotid mass. What is the most common benign tumor of the parotid gland?

Explanation

## Most Common Benign Parotid Tumor **Key Point:** Pleomorphic adenoma (mixed tumor) accounts for approximately 60–70% of all parotid tumors and 80% of benign parotid neoplasms. ### Epidemiology & Pathology - **Incidence:** Most frequent salivary gland tumor overall - **Age of presentation:** Typically 40–60 years - **Origin:** Arises from intercalated ducts; contains both epithelial and myoepithelial components - **Growth pattern:** Slow, painless, often mobile ### Clinical Features - Painless swelling, usually in the superficial lobe - Mobile mass with intact overlying skin - No facial nerve involvement (unless malignant transformation occurs) - Risk of malignant transformation (~2–5% over 15 years if untreated) ### Histology - Mixed epithelial and mesenchymal (connective tissue) elements - Myxoid, chondroid, and osseous differentiation - Encapsulated but not truly benign in behavior (recurrence risk if incompletely excised) ### Management - Superficial parotidectomy with facial nerve preservation is the gold standard - Enucleation alone carries high recurrence risk **High-Yield:** Pleomorphic adenoma is the **single most common parotid tumor** in all age groups and the most frequent benign salivary gland neoplasm worldwide. | Feature | Pleomorphic Adenoma | Warthin Tumor | Oncocytoma | |---------|-------------------|---------------|------------| | **Frequency** | 60–70% of parotid tumors | 5–15% | 1–2% | | **Age** | 40–60 years | 50–70 years (older) | 60+ years | | **Gender** | Equal | M > F | M > F | | **Location** | Superficial lobe | Superficial lobe | Superficial lobe | | **Malignant potential** | 2–5% | None | None | [cite:Robbins 10e Ch 16]