Types of salivary gland cancer

The salivary glands are made up of a number of different types of cells. For example, there are acinic cells, which make and release saliva. And mucoepidermoid cells that line the gland. The type of cancer you have is named after the type of cell the cancer started in. The doctor needs to take a biopsy and a specialist looks at the cells under a microscope before they can tell which type it is. So your doctor will tell you which salivary gland is affected and the cell type.

Most tumours of the salivary gland are not cancer, they are benign. This is especially so for parotid cancer where 3 out of 4 tumours (75%) are benign.

The symptoms are similar whether a tumour is a cancer or a benign lump. You usually notice a painless lump or swelling on or near your jaw or in your mouth or neck. There are different types of benign tumours. The most common type are pleomorphic adenomas (pronounced play-o-morf-ik ad-en-oh-mars).

Your doctor is likely to suggest surgery to remove these as there is a small risk of a cancer developing within the tumour. If these benign tumours are likely to come back again you may have a course of radiotherapy.

Mucoepidermoid  (pronounced mew-co-ep-ee-derm-oyd) cells are the lining cells of the salivary glands. Cancers of this type form tiny, mucous filled cysts.

Most of these cancers develop in the parotid gland but they can also develop in the submandibular glands. The parotid and submandibular glands are types of major salivary glands. Mucoepidermoid cancers can also develop in the minor salivary glands.

Most mucoepidermoid cancers are slow growing (low grade) but they can be fast growing (high grade). With this type of cancer, about a third of people have pain or some sort of paralysis of part of the face as a symptom.

Acinic (pronounced a-sin-ik) cell carcinomas are slow growing. These cancers develop in the acinar cells which produce saliva. This type of tumour is more common in women than men.

About 15 out of every 100 salivary gland cancers (15%) are adenoid cystic cancers. They are the most common type of cancer that develops in the minor salivary glands. They are usually slow growing – your doctor may say the cancer is low grade.

Adenocarcinomas are rare cancers of the salivary gland. They develop in the epithelial cells – the lining cells of the body. They can develop in the major or minor salivary glands.

Malignant mixed cell cancers are similar to the most common benign tumour of the salivary gland (pleomorphic adenoma). A small number of people who have a benign tumour go on to develop a malignant mixed cancer.

Polymorphous (pronounced polly-morf-us) just means that the cancerous tissue has a variety of different growth patterns when seen under a microscope. These are slow growing cancers. Although very rare, they are the second most common cancer of the minor salivary glands. They are most common in people over the age of 70 years.

There are a number of other even rarer types of salivary gland cancer including

• Squamous cell carcinoma
• Lymphoepithelioma
• Anaplastic carcinoma
• Poorly differentiated carcinoma
• And other even rarer cancers

These tend to develop later in life and are usually fast growing cancers.