Parotid Gland Tumours

The parotid gland is the largest of the salivary glands and lies just in front of the ear, above the angle of the jaw. The great majority of salivary gland tumours develop in this gland, and most of them are benign. Because the facial nerve, which controls the movements of the face, runs through the gland, the treatment of parotid tumours requires special attention.

The parotid gland and the facial nerve

The parotid gland is divided by the branches of the facial nerve into two parts, superficial and deep. Most tumours are located in the superficial part. The facial nerve controls movements such as wrinkling the forehead, closing the eye, smiling and pursing the lips. The relationship of the tumour to the nerve is therefore decisive both in diagnosis and in treatment planning.

Symptoms

• A painless, slowly growing lump in front of the ear or below the earlobe
• A lump that becomes noticeable over months or years
• Rarely, pain, a feeling of fullness in the ear or discomfort when chewing
• Weakness on one side of the face, inability to close the eye fully or drooping of the corner of the mouth

Benign tumours usually cause nothing but a lump. Pain, rapid growth, redness of the skin or weakness of the facial nerve are warning signs of a malignant tumour.

Diagnosis

During the examination, the size, consistency and mobility of the mass are assessed and the function of the facial nerve is checked. Ultrasound is the first imaging method; fine-needle aspiration biopsy gives preliminary information about the type of tumour. For tumours located in the deep part or suspected of being malignant, magnetic resonance imaging (MRI) shows the borders of the tumour and its relationship to the nerve. The definite diagnosis is made by pathological examination of the tissue removed at surgery.

Treatment

The treatment of parotid tumours is surgical; the operation is called a parotidectomy. In benign, superficially located tumours, the superficial part of the gland is removed together with the tumour (superficial parotidectomy). In deep-seated or malignant tumours, the whole gland may be removed (total parotidectomy). In both cases the facial nerve and its branches are identified, exposed and protected; a nerve monitoring device (neuromonitor) may be used during the operation. In malignant tumours, removal of the lymph nodes of the neck and radiotherapy may be needed depending on the pathology result.

After surgery

The incision is usually made along a line that starts in front of the ear and extends to the upper part of the neck, hidden in the natural creases. Mild swelling and tenderness for a few days after surgery are normal. Temporary weakness of the facial nerve may occur; when the nerve has been preserved, this weakness usually resolves within weeks or months. Numbness around the earlobe is common and usually decreases with time. Some people develop sweating or flushing over the operated area while eating (Frey’s syndrome); this is usually mild and can be treated if necessary.

When should you see a doctor?

If you notice a persistent lump in front of the ear, a growing or painful mass, or weakness on one side of your face, it is advisable to seek an evaluation.