What is the management of pleomorphic adenoma of the parotid gland?

Management of Pleomorphic Adenoma of the Parotid Gland

The definitive management of pleomorphic adenoma of the parotid gland is surgical excision with appropriate margins, with the specific surgical approach determined by tumor location and characteristics. 1

Surgical Approach Based on Tumor Characteristics

The surgical approach should be tailored according to the following parameters:

• For superficial lobe tumors (most common - 81.7% of cases) 2:

  • T1 or T2 low-grade: Partial superficial parotidectomy
  • Larger tumors: Superficial (exofacial) parotidectomy

• For deep lobe tumors:

  • Total parotidectomy is recommended 2

• For recurrent disease:

  • Revision surgery with consideration of total parotidectomy and neck dissection 1
  • Previous scar should be excised during the procedure 3

Surgical Technique Considerations

1. Facial nerve preservation:

   • Preservation should be performed when preoperative function is intact
   • Create a dissection plane between tumor and nerve
   • Facial nerve branch resection only when preoperative movement is impaired or branches are encased by confirmed malignancy 1

2. Capsule integrity:

   • Complete excision without perforation of the capsule/pseudocapsule is crucial
   • Avoid dissection near the tumor capsule, which is the major cause of recurrence 3
   • "En-bloc" resection technique is preferred 4

3. Intraoperative considerations:

   • Intraoperative pathologic examination may guide extent of resection
   • Frozen section accuracy: 99% for identifying neoplastic lesions 1
   • Meticulous hemostasis and layered wound closure are essential 1
   • Maintaining thick skin flaps when oncologically appropriate reduces complications 1

Outcomes and Complications

Recurrence Rates

• Very low (0.8%) with appropriate surgical technique 1
• Higher risk factors for recurrence:
  • Previous incomplete surgery
  • Positive margins
  • Capsule infiltration 2

Facial Nerve Function

• Temporary facial weakness: approximately 27% of cases
• Permanent facial weakness: 2.5% of patients with normal preoperative function 1
• Transitory facial paralysis is higher after total parotidectomy compared to superficial procedures 2

Other Complications

• Frey syndrome (gustatory sweating)
• Greater auricular nerve anesthesia
• Hematoma formation
• Salivary fistula 1
• Depression or swelling at the surgical site 5

Post-Surgical Management

• Regular follow-up is essential as recurrences can develop years after surgery 1
• For recurrent cases, particularly those extending into the parapharyngeal space, postoperative radiotherapy may be considered 6
• Patient education about potential delayed onset of symptoms is important 1

Surgical Approach Comparison

Research comparing superficial parotidectomy (SP) with retrograde partial superficial parotidectomy (PSP) found:

• PSP had shorter surgical time (145 vs 171 minutes)
• PSP preserved more healthy parotid tissue
• PSP had significantly fewer facial nerve injuries (10% vs 61%)
• However, Frey syndrome was more common with PSP 5

Special Considerations

• For tumors extending into the parapharyngeal space, combined surgical approaches may be necessary (e.g., cervical-transparotid and mandibular swing approach) 6
• MRI is crucial for assessing tumor extent, particularly for deep lobe involvement or parapharyngeal extension 6
• The close proximity of vital neurovascular structures requires careful preoperative evaluation 6