Tumours of the salivary glands are rare. The majority of salivary gland tumours occur in the large parotid gland that wraps around the vertical posterior part of the lower jaw. In this gland, 75–80% of tumours that do occur are benign, with the majority of these being a benign tumour called pleomorphic adenoma. Although much less frequent, salivary gland tumours also occur in the other major salivary glands, called the submandibular glands and the sublingual glands, as well as in the minor salivary glands. The latter are widely distributed in the oral cavity and oropharynx. Sites in the oral cavity include the lips, the cheeks, the floor of the mouth and the palate.