Benign Minor Salivary Gland Tumors (Pleomorphic Adenoma, Monomorphic Adenoma, Warthin’s Tumor)

Epidemiology

A minor salivary gland consists of cellular constituents of the major salivary glands (parotid, submandibular, sublingual) that are located within the mucosa of the upper aerodigestive tract. It has been estimated that there are between 500 and 1000 minor salivary glands located throughout the oral cavity and oropharynx. They may be found within the hard and soft palate, uvula, lips, retromolar trigone, tongue base, floor of mouth, and tonsil. The same malignancies that arise in the major salivary glands occur in the minor salivary glands. Depending on the series, approximately 50% of minor salivary gland tumors are benign as compared with approximately 70 to 80% of parotid tumors that are benign.

Clinical Findings

Patients often present with asymptomatic masses that have been present for several months. Pain and ulceration may be present; however, these are not consistent findings. Patients with tumors arising in the larynx may present with symptoms of airway obstruction.

Pathology

The benign lesions that constitute minor salivary gland tumors include pleomorphic adenoma, monomorphic adenoma, and Warthin’s tumor. The pathology of these lesions has been reviewed in other sections of this textbook.