Salivary gland neoplasm

What it is

Parotid gland neoplasms are the most common salivary gland neoplasm, and 80% of salivary gland tumors are benign.

Benign:

• Pleomorphic adenoma, which is the most common benign parotid swelling.
• Warthin tumor, seen in elderly males.
• Lymphoepithelioma, oncocytoma and monomorphic adenoma.

Malignant tumours have 5 histological types, and the commonest is mucoepidermoid.

How it presents

The mass is painless. A pleomorphic adenoma is slow growing, smooth and mobile. A malignant tumour is a painless rapidly growing mass that may invade the skin, with cervical lymphadenopathy and constitutional symptoms.

Facial nerve involvement, that is facial paralysis, increases the risk of malignancy, and CN VII palsy is part of the malignant picture. A parotid tumour is also one of the causes of facial weakness of both the upper and the lower face.

How it is diagnosed

Investigations are FNA biopsy, CT, US and MRI, and FNAC should be done.

The facial nerve passes via the parotid gland, so if a patient has facial nerve paralysis this is malignancy until proven otherwise.