context: Adenoid cystic carcinoma is a rare kind of cancer that usually starts in the glands that make saliva. These are under your tongue and on each side of your jaw below the jawbone. But it also can occur in other parts of your mouth and throat or other areas of your body, such as your sweat glands or tear glands. Of the 500,000 people who get cancer each year, about 1,200 of them have adenoid cystic carcinoma. It affects more women than men, and it can happen at any age between your teens and your 80s. It tends to grow slowly, so it sometimes can spread to other parts of your body before you notice any symptoms. It can come back in places where it's been treated before or spread to your lungs, liver, or bones, where it's more serious. Doctors don't know what causes adenoid cystic carcinoma. It may be linked to some carcinogens, like pollution or asbestos. The first sign may be a lump inside your mouth under your tongue or inside your cheek. These lumps usually grow slowly and don't hurt. You might have some trouble swallowing, or your voice might sound hoarse. This type of cancer can spread along nerves, so you might have some pain or numbness in your face. If you notice any of these symptoms, see your doctor. If your doctor thinks you might have adenoid cystic carcinoma, the first step is often a biopsy. She'll take a small sample of the tumor, either after making a small cut or with a needle. A pathologist, a doctor who specializes in the study of diseases, will study the sample to look for signs of cancer. These kinds of tumors can take different forms. They can be solid or round and hollow like a tube, or cribriform, which means they have holes in them like Swiss cheese. The solid tumors usually grow faster. Your doctor might want to find out the size and location of a tumor or look for signs the cancer has spread. You might have one of these tests: MRI (magnetic resonance imaging): Powerful magnets and radio waves are used to make detailed images. CT scan (computerized tomography): Several X-rays taken from different angles are put together to show more information. PET scan (positron emission tomography): Radiation is used to make 3-dimensional color images. The usual treatment for adenoid cystic carcinoma is surgery followed by radiation treatments. When you have surgery, your doctor will remove not only the tumor but also some of the healthy tissue around it. He'll look at that tissue to make sure the cancer hasn't spread beyond the tumor. Unlike many other cancers, which can go to other parts of your body through your lymph nodes, adenoid cystic carcinoma spreads along your nerves. Your doctor will look at your nerves to make sure the cancer isn't in the area around them and will try to remove any cancerous tissue without damaging them. Sometimes, part of a nerve may have to be removed to get all the cancer out. That can mean you won't be able to move part of your face or it might droop. Your doctor may try to reconnect the damaged nerve with part of another nerve so you can move the affected area. Other times, part of your windpipe or voice box has to be removed. If your doctor can't take out the entire tumor without hurting important organs, or if he's worried the cancer has spread somewhere he hasn't seen, you may have radiation treatments. There are three main kinds: External beam radiation focuses high-energy X-rays or protons on cancer cells to destroy them. Your doctor will try to do as little damage as possible to the surrounding parts of your body. Internal radiation therapy is also known as brachytherapy. Your doctor will put small radioactive "seeds" at or near the tumor. This is often used when cancer has spread to the lungs. The radioactivity of the seeds lessens after a few weeks. Neutron therapy can target small tumors by heating up the cells with 100 times more energy than regular radiation treatment. That often kills cancer cells while letting the normal cells around them recover. Radiation therapy focused on your head and neck has side effects that can include dry mouth, difficulty swallowing, or soreness around the area that's being treated. It can also damage your teeth. Check with your doctor about these side effects and ask what she can do to help you with them. It can be hard to get rid of the cancer entirely. Tumors may come back years later, either in the same place or, more likely, somewhere else -- usually in your lungs. Most people who have adenoid cystic carcinoma live at least 5 years after their diagnosis. After your treatment, you'll need regular checkups to look for signs of new tumors. This can involve X-rays, CT scans, or MRIs, depending on your diagnosis.