Parotid tumors

Benign (80%)

• Pleomorphic adenoma (70%)
  • aka Benign mixed tumor
  • Calcifications (unlike Warthin's)
  • Malignant transformation reported up to 15% if left untreated
• Warthin's tumor
  • aka Papillary cystadenoma lymphomatosum
  • M>F
  • Hot on 99mTc-Pertechnetate (pleomorphic adenoma cold)
  • Malignant transformation (carcinoma or lymphoma) reported in < 1%

Malignant (20%)

• Mucoepidermoid carcinoma (5%)
• Carcinoma arising from pleomophic adenoma
• Adenoid cystic carcinoma = cylindroma (2%)
• Adenocarcinoma (4%)
• Squamous cell carcinoma (2%)
• Oncocytic carcinoma (1%)