Salivary Gland Tumours

Salivary gland tumours are masses that form when cells in the saliva-producing glands multiply uncontrollably. The great majority are benign and grow slowly; however, some may be malignant. For this reason, any lump noticed in the region of the salivary glands should be evaluated by a doctor.

The salivary glands and their tumours

There are three pairs of major salivary glands: the parotid gland in front of the ear, the submandibular gland under the jaw and the sublingual gland under the tongue. In addition, hundreds of minor salivary glands are found in the lining of the lips, cheeks, palate and throat. Tumours occur most often in the parotid gland, and most tumours in this gland are benign. The smaller the gland, the higher the likelihood that a tumour is malignant; masses in the submandibular and minor salivary glands are therefore assessed with greater care.

Benign and malignant tumours

• Benign tumours: The most common type is the pleomorphic adenoma, which forms a well-defined, slowly growing mass. Because it can, rarely, turn malignant when left for many years, its removal is recommended. Warthin’s tumour is another common benign type that does not undergo such transformation.
• Malignant tumours: There are various types, such as mucoepidermoid carcinoma, adenoid cystic carcinoma and acinic cell carcinoma. Their behaviour depends on the type and grade; some progress slowly, others quickly.

Symptoms

• A painless, slowly growing lump in front of the ear, under the jaw or inside the mouth
• Rapid growth of the lump, hardening, or a feeling that it is fixed to the surrounding tissue
• Pain, numbness or weakness of the facial muscles
• Difficulty opening the mouth or swallowing

Pain, rapid growth and facial nerve symptoms may suggest a malignant tumour; however, these symptoms can also occur in benign conditions.

Diagnosis

The evaluation begins with a head and neck examination. Ultrasound shows the structure of the gland and the features of the mass; the cells obtained by fine-needle aspiration biopsy provide information on whether the tumour is benign or malignant. For deep-seated tumours or those suspected of being malignant, magnetic resonance imaging (MRI) or computed tomography (CT) is used to assess the extent of the tumour. The definite diagnosis is made by pathological examination of the removed tissue.

Treatment

The main treatment for salivary gland tumours is surgery. In benign tumours, the tumour is removed together with a margin of healthy tissue around it; in the parotid gland, the facial nerve is carefully protected. In malignant tumours, the whole gland and, when necessary, the lymph nodes of the neck are removed; radiotherapy may be added after surgery depending on the pathology result. The treatment plan is tailored to the individual according to the type, grade and location of the tumour.

When should you see a doctor?

If you notice a lump in front of the ear, under the jaw or inside the mouth that has not gone away for a few weeks, if the lump is growing or painful, or if you feel weakness or numbness on one side of your face, it is advisable to seek an evaluation. Early diagnosis makes treatment simpler and its results more predictable.