Saliva has an important role in the preparation of food for digestion by the stomach, and in the lubrication of the mouth, pharynx and voicebox. There are three paired major salivary glands – the parotid glands in front of the ears, the submandibular glands below in jaw and the sublingual glands in the floor of the mouth. There are also hundreds of smaller 'minor' salivary glands that produce saliva. There are many diseases that affect the salivary glands.
Tumours or masses within the salivary glands may be benign or malignant. Eighty percent of parotid tumours are benign whereas only 60% of submandibular gland tumours and a small percentage of minor salivary gland tumours are benign. There are more than 20 varieties of salivary gland cancers – the most common variety is a mucoepidermoid carcinoma which maybe low, intermediate or high grade.
Salivary gland cancers usually present as painless lumps in the neck. Mucoepidermoid cancers may occasionally be painful so the dictum that painful lumps are less likely to be malignant does not apply.
The most common benign salivary gland tumour is a pleomorphic adenoma. Although benign, these have a tendency to recur after surgical removal. It is important that surgery for pleomorphic adenomas is performed well to ensure complete removal and no tumour spillage during extirpation.
Salivary gland infections or sialadenitis are common. They occur in those who do not drink adequately and in the elderly. Some infections may develop into abscesses that require drainage. Most infections are self-limiting and resolve well with antibiotics.
Salivary gland stones are common in the submandibular gland. Small stones may extrudespontaneously. Some stones may be treated with sialendoscopy which utilizes fine scopes to examine the ducts of these glands and removed any stones.
Cysts may arise from the ducts of salivary glands. The picture below is of a cyst called a plunging ranula. There is evidence of a cyst in the floor of mouth as well as protrusion of this cyst into the neck.
Surgery for removal of the major salivary glands includes a parotidectomy for masses in the parotid gland. This surgery involves operating close to the facial nerve. I routinely use a nerve monitor for these operations to ensure optimal outcome. In cases of cancer, it may be necessary to perform a neck dissection to remove the lymph nodes in the neck.