There are two parotid glands in the body - one on each side of the face. Their job is to secrete saliva into the mouth, along with the submandibular glands and the many minor salivary glands all over the lining of the mouth and throat. Occasionally, a lump can develop in the gland and start to grow. Normally, these lumps are painless and grow slowly.
80% of parotid lump are benign and 80% of these are pleomorphic adenomas. I would examine your mouth and throat, neck, ears and check the inside of your nose and throat with a camera to make sure there are no other lesions seen. I also check to see that your face is moving as each parotid gland has a facial nerve running through it which is responsible for moving that half of the face. If the some or all the face is not moving, there is a high chance the lump is cancerous and has damaged the facial nerve.
I would normally ask for you to have an ultrasound scan and biopsy of the neck, so we can get a sample of the tumour sent off to the lab and we can see what we are dealing with. Most of the time an operation will be necessary to remove part or all of the parotid gland. This is to remove the lump and to send it off to the lab, so it can be checked to make sure it is benign. If the tumour looks particular to be particularly deep or large then I might ask you to have an MRI scan. If the tumour looks cancerous, you may need a CT scan of your body to make sure it has not spread.
You might ask why we remove these lumps if most are benign and not causing you any issues. The reason is that we cannot be absolutely sure, from the preoperative biopsies, that the tumour is benign. If the tumour proves to be cancerous, most patients will require additional treatment with radiotherapy, after surgery, to kill of any remaining microscopic cancer cells.
Secondly, every year a pleomorphic adenoma is left in place, 1% turn cancerous. I have seen a patient who left her parotid tumour alone for 30 years, and she came to us when it had turned cancerous and spread to the liver. Once it has spread, it cannot be cured.
A parotidectomy operation is one of the most technically challenging operations that I do. It is a major operation. Not only do I have to remove the tumour, but I have to preserve the facial nerve that is responsible for moving the face and runs through the middle of the gland. If the nerve has already been damaged by a cancer, I might have to remove it during the surgery. Imagine that the parotid gland is two slices of bread with jam in the middle. In the middle of the jam is a spider’s web (the facial nerve). My task is to remove the top slice of bread, whilst identifying the spider’s web and tracing it out, preserving all its delicate strands without breaking any of the strands. Sometime the tumour is deep to the facial nerve. This is even more of a technical challenge, as I have to remove the top and bottom slice of bread whilst preserving the spider’s web!
You come into hospital, and have a general anaesthetic so you are fully asleep. I make an incision which runs in the crease in front of your ear and down into your neck. I can often find a crease in the neck in which to hide the incision line. I lift the skin off the parotid gland. Then, I find the muscles in the neck which help me identify the depth of the facial nerve. Then I use delicate forceps to spread the parotid tissue and find the nerve. Once I find the nerve, I use a special probe connected to an electronic monitor to touch the nerve and pass a current through it. If I have correctly identified the nerve, the monitor will beep and the face will twitch. Then, I trace out the nerve whilst cutting in a 3 dimensional manner around the lump. I must not cut into the lump, otherwise cells can leak out causing a recurrence of the lump years down the line (if it is a pleomorphic adenoma). Once I have removed the lump along with a cuff of normal parotid tissue, I place it into a pot and send it off to the lab to be checked for cancer under the microscope. I place a drain (a plastic tube connected to a bottle) through the skin to remove any excess fluid which collects. I suture the skin with absorbable stitches and put glue on top to make it waterproof, so you can shower after the surgery. The wound is raised and red on purpose.
You stay in hospital until the drain stops draining fluid into the attached bottle, and the nurses remove it. This means that most people stay in hospital for 2 to 3 nights. You need to have 2 weeks at home after the surgery, to prevent any wound infection. It would be better not to do any heavy lifting for 4 weeks after surgery. After 2 weeks the glue will turn grey and you, or I, can remove it. After a few months the wound will flatten to create a faint scar. Most of the time, this won’t be visible as it heals so well.
The risks are pain, bleeding, infection, general anaesthetic, temporary or permanent facial paralysis, collection of blood of fluid under the surface of the skin, numbness around the ear and the face, spill of tumour, recurrence, sweating and flushing of the skin after eating (Frey’s syndrome). If you have COVID and have a general anaesthetic there is a 20% risk of mortality, so it is important to do lateral flow tests, in the lead up to surgery, and avoid mixing with large groups in the lead up to surgery. If you get COVID, this may result in a 7-week delay to surgery.
It is common for the cut edges of the tissue of the parotid gland to carry on secreting fluid under the surface of the skin. This egg-like swelling is called a seroma. It is not unusual. Every couple of weeks, you come to clinic, and I can use a needle and syringe to tap off the fluid. Each time it is done, less fluid reaccumulates, until finally it dries up. It is not a good idea to tap the fluid off daily, as this may change a sterile collection of fluid into an abscess or infection. Most people feel numb around the neck and ear after surgery, but this tends to improve over 6 months. Some people have a bit of temporary weakness in facial movement after the surgery. This is because the nerve can be stretched by the surgery. It can take a few months to recovery.
A permanent facial paralysis is unusual, unless the nerve has already been damaged by a cancer and has been removed. In this situation, I work with a plastic surgeon to try and correct some of the asymmetry of the face using special techniques. If you cannot close your eye after surgery, you must tape the eye shut when you sleep, on that side, to make sure it doesn’t dry out, and use eye drops to keep it moist.