Table of Contents
Overview – Salivary Gland Tumours
Salivary gland tumours are uncommon neoplasms that most frequently arise in the parotid gland. The vast majority are benign, with pleomorphic adenoma and Warthin’s tumour being the most common types. Diagnosis relies on imaging and biopsy, while treatment generally involves surgical excision due to the potential for malignancy or recurrence.
Pleomorphic Adenoma
Definition
- Benign epithelial neoplasm of the salivary glands.
- Most common salivary gland tumour (~80%), and most frequently affects the parotid gland.
Aetiology
- Unknown.
- Strongly associated with cigarette smoking.
Pathogenesis
- Slow-growing, benign tumour with architectural pleomorphism.
- May undergo malignant transformation into carcinoma ex pleomorphic adenoma.
Morphology
Macroscopic:
- Enlarged, firm, mobile parotid mass.
Microscopic:
- Heterogeneous appearance:
- Cysts lined by squamous epithelium
- Myxoid (mucoid), chondroid (cartilaginous) areas
- Trabeculae, ductal structures (adenomatous origin)
- Fibrous pseudocapsule surrounds the tumour (not a true capsule).
Clinical Features
- Adults (any age)
- Painless, slow-growing firm mass in the parotid region
- Asymptomatic unless large or compressive
- Risk of malignant transformation over time
Investigations
- Fine needle aspiration biopsy (FNAB)
- CT/MRI to assess tumour size and local extension
Treatment
- Surgical excision is the gold standard
- Enucleation alone is avoided due to risk of recurrence
Warthin’s Tumour
Also known as
- Papillary Cystadenoma Lymphomatosum
Definition
- Benign salivary gland tumour with lymphoid and epithelial components
- Accounts for ~10% of all salivary gland tumours
Aetiology
- Unknown
- Strongly associated with smoking
- Occurs almost exclusively in the parotid gland
Morphology
Macroscopic:
- Well-defined cystic lesion in the tail of the parotid gland (near mandibular angle)
Microscopic:
- Cystic spaces lined by double-layered epithelium
- Central pyknotic nuclei, with lymphoid stroma and germinal centres
Clinical Features
- Typically affects older males (60–70 years)
- Painless, slow-growing parotid swelling
- Often bilateral or multifocal
- Risk of malignant transformation is low but documented
Investigations
- Fine needle aspiration biopsy (FNAB)
- CT or MRI to assess extent
Treatment
- Surgical excision is standard
- Recurrence is rare
Summary – Salivary Gland Tumours
Pleomorphic adenoma and Warthin’s tumour are the most common benign tumours of the salivary glands, particularly the parotid. Both present as slow-growing, painless masses and require imaging and biopsy for diagnosis. Due to the risk of recurrence and potential malignant transformation, surgical excision remains the definitive treatment.
For broader context, visit our Head and Neck Overview page.