Treatment of Classic Pleomorphic Adenoma
Complete surgical excision with preservation of the facial nerve is the definitive treatment for pleomorphic adenoma of the salivary glands, achieving local control rates of 95% or higher. 1
Surgical Approach
For Major Salivary Glands (Parotid)
Superficial parotidectomy or partial superficial parotidectomy is the standard surgical approach, with the goal of complete excision outside the tumor capsule while preserving the facial nerve. 2, 1
Retrograde partial superficial parotidectomy may be superior to classical superficial parotidectomy in appropriately selected cases, demonstrating shorter operative time (145 vs 171 minutes), less healthy tissue removal, and significantly fewer facial nerve injuries (10% vs 61% temporary deficits). 3
The entire gland should be completely excised for major gland tumors to ensure adequate margins and prevent recurrence. 2
Enucleation alone is inadequate as it results in higher recurrence rates and should be avoided. 4
For Minor Salivary Glands
Wide radical resection with extended excision is required for minor salivary gland pleomorphic adenomas. 2
Complete excision outside the capsule/pseudocapsule is mandatory in all cases. 5
Key Surgical Principles
The facial nerve must be preserved during parotid surgery, as nerve sacrifice is not justified for benign disease. 4, 6
Intraoperative frozen section can be utilized to confirm benign diagnosis and guide the extent of resection, though this is more commonly employed when malignancy is suspected. 5
Capsular perforation must be avoided during dissection, as tumor spillage increases recurrence risk significantly. 3
Role of Radiotherapy
Radiotherapy is NOT indicated for completely excised pleomorphic adenomas with negative margins. 7
However, radiotherapy becomes useful in specific scenarios:
Positive surgical margins: Local control rates of approximately 80-85% for microscopic residual disease. 1
Unresectable tumors: Local control rates of 40-60% for gross residual disease. 1
Multifocal recurrences after prior resection: Radiotherapy can achieve local control when repeat surgery is not feasible. 1
Common Pitfalls to Avoid
Do not perform simple enucleation, as this violates the pseudocapsule and leads to recurrence rates significantly higher than formal parotidectomy. 4
Do not sacrifice the facial nerve for a benign tumor—complete excision with nerve preservation is achievable in the vast majority of cases. 5, 4
Do not underestimate the risk of malignant transformation in longstanding untreated tumors—carcinoma ex-pleomorphic adenoma has a 75% five-year recurrence rate. 6
Expected Outcomes
Local control rates exceed 95% with appropriate surgical excision. 1
Temporary facial nerve weakness occurs in 10-61% depending on technique, but permanent deficits should be rare (under 10%) with experienced surgeons. 3
Frey syndrome develops in approximately 27.7% of patients post-parotidectomy. 3
Recurrence occurs in less than 5% when complete excision with intact capsule is achieved. 3