What is the diagnosis and treatment of pleomorphic adenoma of the salivary gland (parotid gland)?

From the Guidelines

Pleomorphic adenoma of the salivary gland should be treated with complete surgical excision, prioritizing preservation of surrounding structures, particularly the facial nerve, to minimize complications and prevent recurrence. The goal of surgery is to achieve complete excision of the tumor while preserving the facial nerve and other important structures 1. For parotid pleomorphic adenomas, superficial parotidectomy with facial nerve preservation is a recommended approach, as it allows for complete tumor removal while minimizing the risk of facial nerve injury 1. Key considerations in the management of pleomorphic adenoma include:

• Complete surgical excision to prevent recurrence
• Preservation of the facial nerve and other surrounding structures
• Minimizing complications such as facial nerve injury
• Regular follow-up after surgery to monitor for potential recurrence The clinical behavior of pleomorphic adenomas is similar to that of low-grade salivary gland cancers, which can be managed with partial superficial parotidectomy for appropriately located superficial T1 or T2 tumors 1. However, the primary goal in treating pleomorphic adenoma is to achieve complete excision of the tumor while preserving surrounding structures, rather than removing additional parotid tissue or lymph nodes 1. By prioritizing complete surgical excision and preservation of surrounding structures, patients with pleomorphic adenoma of the salivary gland can expect an excellent prognosis and low risk of recurrence 1.

From the Research

Overview of Pleomorphic Adenoma of Salivary Gland

• Pleomorphic adenoma is the most common benign salivary gland neoplasm, found mostly in the parotid gland in middle-aged women 2.
• It progresses slowly and, left untreated, can produce significant morbidity and, rarely, death 2.

Treatment and Outcomes

• The optimal treatment is superficial or total parotidectomy with facial nerve preservation, which results in local control rates of 95% or higher 2.
• Radiotherapy (RT) is useful to obtain local control in patients with positive margins, unresectable tumors, and multifocal recurrences after prior resection 2.
• Local control rates after RT for microscopic and gross residual tumor are approximately 80% to 85% and 40% to 60%, respectively 2.

Malignant Transformation

• Malignant transformation of pleomorphic adenoma occurs in 5 to 25% untreated patients, usually after 15-20 years 3.
• Warning symptoms of malignant transformation are present in most cases, including rapid enlargement of tumor, pain, and facial nerve palsy 3.
• Fine needle aspiration biopsy has insufficient sensitivity and accuracy in detection of malignant character of pleomorphic adenoma 3.

Surgical Management

• Surgical treatment, alone or with postoperative irradiation, allows for good locoregional control of carcinoma ex pleomorphic adenoma (CXPA) 3.
• The best method of prevention and treatment of CXPA is early and radical removal of all major salivary glands tumors 3.
• Histopathological characteristics of pleomorphic adenomas, such as capsular alterations, are important for the choice of surgical treatment and the first explanation for tumor recurrence 4.

Patient Characteristics and Outcomes

• The mean age of pleomorphic adenoma occurrence is 44.14 years with a definite female predilection (M:F ratio = 13:8) 5.
• Pleomorphic adenomas most commonly occur in the facial region (42.85%) 5.
• Complete excision of the tumor is the definitive treatment, as enucleation can result in recurrence 5.
• Determinate survival at 5 years for CXPA is 73.6% and in the group treated surgically (alone or with postoperative irradiation) 87.5% 3.