salivary gland cancer
Meaning of salivary gland cancer: An uncommon head and neck cancer whose behavior depends far more on the microscope findings than on its size.
Definition of salivary gland cancer
Salivary gland cancer is a malignant growth in one of the glands that produce saliva. Most begin in the parotid gland in front of the ear, although a lump in one of the smaller glands is more likely to be cancerous when one appears. Many microscopic types exist, and they range from slow and quiet to fast and aggressive.
Which glands can be affected?
Three pairs of major glands and hundreds of tiny minor ones line the mouth and throat. A rule of thumb runs through the whole group: the smaller the gland, the greater the chance that a lump in it is malignant rather than benign.
| Gland | Where it sits | Lumps found there |
|---|---|---|
| Parotid | In front of and below the ear | Mostly benign |
| Submandibular | Under the jawbone | Intermediate |
| Sublingual and minor glands | Floor of mouth, palate, lips | Mostly malignant |
How does it show itself?
A painless lump is the usual first sign, and on its own it says nothing about whether the growth is benign. Features that raise concern are steady enlargement, pain, a hard feel and fixation to the tissue beneath. Weakness of the face on the same side matters most of all, because the facial nerve runs straight through the parotid salivary gland. A benign lump pushes that nerve aside, while a cancer can grow into it. Numbness, difficulty opening the mouth and enlarged neck nodes point the same way.
What are the microscopic types?
Pathologists recognize more distinct types here than in almost any other organ, and the type predicts behavior better than the size does. Mucoepidermoid carcinoma is the commonest and is graded from low to high. Adenoid cystic carcinoma grows slowly but creeps along nerves and can return many years later. Acinic cell carcinoma is usually quiet. Cancer can also arise inside a long-standing benign tumor. Because a needle sample is often hard to interpret, the final type is frequently settled only after the gland has been removed. Parotid gland cancer is the group met most often, simply because that gland is the largest.
What is known about the causes?
Most cases have no identified cause. Previous radiation to the head and neck is the clearest risk factor. Certain workplace exposures, including rubber manufacturing and nickel dust, have been linked to it. The connection with tobacco and alcohol is weak, unlike cancers of the mouth lining, and the tumor most strongly tied to smoking in this region is a benign one. The glands are affected as tissue rather than through the saliva they make.
Used in a sentence
The excised parotid mass was reported as a low-grade salivary gland cancer with clear margins.
Good to know
Facial weakness on the same side as a parotid lump suggests the growth has invaded the facial nerve, a feature that points toward cancer rather than a benign tumor.
Word origin
Where “salivary gland cancer” comes from
Salivary comes from the Latin saliva, meaning spittle.