What are the characteristics and treatment of pleomorphic parotid adenoma (benign salivary gland tumor)?

Pleomorphic Parotid Adenoma: Characteristics and Treatment

Pleomorphic adenoma is the most common parotid neoplasm that requires superficial parotidectomy rather than simple enucleation for proper treatment. 1, 2

Key Characteristics

• Epidemiology: Most common benign salivary gland tumor, accounting for 60-70% of all benign parotid tumors 3
• Demographics: Typically occurs in the fourth to sixth decade of life with female predominance 3
• Growth pattern: Slow-growing with a pseudocapsule that often has finger-like extensions into surrounding normal tissue 4
• Malignant transformation: Uncommon (not "common" as suggested in option C)
• Facial nerve involvement: Rarely causes facial nerve palsy preoperatively (contradicting option D)

Diagnostic Approach

Core biopsy is not routinely required before resection of suspected pleomorphic adenomas. The diagnosis is typically made based on clinical presentation and imaging, with definitive diagnosis confirmed by surgical excision and histopathological examination 1.

Surgical Management

Recommended Approach

• Superficial parotidectomy is the standard of care, not enucleation 2
• Enucleation is associated with high recurrence rates due to:
  • Lack of true capsule in pleomorphic adenomas
  • Finger-like extensions into surrounding tissue
  • Risk of tumor spillage during enucleation 4, 5

Surgical Techniques

• Partial superficial parotidectomy has shown excellent results with:
  • Low recurrence rates (0.6-1.7%) 4, 6
  • Reduced risk of facial nerve injury
  • Better cosmetic outcomes
  • Shorter operative times compared to traditional superficial parotidectomy 3, 6

Facial Nerve Considerations

• Facial nerve preservation is standard when preoperative function is intact 1
• Temporary facial weakness occurs in approximately 15-27% of cases 1, 6
• Permanent facial weakness is rare (2.5%) with proper technique 1

Recurrence and Follow-up

• Recurrence rates are very low (0.8-1.7%) with appropriate surgical technique 1, 4
• Higher recurrence risk factors include:
  • Previous incomplete surgery (especially enucleation)
  • Positive margins
  • Tumor spillage during surgery 1

Common Complications

• Temporary facial nerve weakness (15-27%) 1, 6
• Frey syndrome (4-27.7%) 3, 6
• Greater auricular nerve anesthesia
• Salivary fistula
• Hematoma formation 1

Answer to Multiple Choice Question

The correct answer is (e) - pleomorphic adenoma is the most common parotid neoplasm.

Options (a) through (d) are incorrect because:

• (a) Core biopsy is not routinely required before resection
• (b) Enucleation is inadequate treatment due to high recurrence rates
• (c) Malignant transformation is uncommon, not common
• (d) Facial palsy is a rare presentation, not common