It’s the Small Things: Salivary Gland Stones
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Welcome back to the podcast, ladies and gentlemen. This week, we're going to be continuing our series on it's the small things. Now, there are so many little organs and tiny little ducts in our body that can wreak havoc to our patients. One of them is our submandibular glands. That's right. They can become super inflamed like the parotid gland, or they can even develop stones. That's right. You're sensing a trend here. We just finished with gallstones. And now this week, we're going to be talking about sialolithiasis,

or stones that are within the salivary glands and salivary gland ducts. This condition can be extremely painful and very problematic. It's a little bit different than first bite syndrome, which is basically you eat something super sour like a Sour Patch Kid, and suddenly your parotid glands squeeze down with the force of a thousand suns and cause some idiopathic pain that resolves on its own. I'm Dr. Niket Sonpalm, your friendly neighborhood internist and gastroenterologist, and join me this week where we discuss salivary gland stones.

Now before we can discuss the stones and why they happen, and more importantly what to do about them, we have to do a little bit of review of anatomy. Now there are several glands, but the major ones are the ones that get stones. This includes the parotid, the subbandibular, and the sublingual. Now you know you have a minor salivary gland, but the odds of that one getting a stone are pretty rare.

Now, the parotid gland flows saliva into your body through Stenson's duct. These are located on the sides of the face and they're anterior to the external auditory canal. They're right above your mandible and just below your zygomatic arch. Now, what you have to remember is that Stenson's duct arises from it and it's about four to seven centimeters long and it's not that big. It's only two to three millimeters in diameter.

The submandibular gland empties into your body through Wharton's duct, and this one basically is about 5 centimeters long and only 1.5 millimeters in diameter.

The sublingual glands are just below the membrane of the floor of the mouth. And all of these, their whole purpose is to create saliva and help you with various forms of lubricating the food so it goes down your esophagus properly. And also to get started with a little bit of carbohydrate breakdown because there's some amylase in the actual saliva. Now the term sialolithiasis is great because sialon means saliva and lithos means stone. So it's pretty obvious that you've got a stone sitting in that area.

But what's concerning is we don't actually understand why they happen. The pathogenesis is unknown. We know there's a few theories and a couple of things that are playing a role. Number one, we know that salivary flow is not moving as well as there should be and there's some stasis there. We also know that calcium levels can play a role and if you have high salivary calcium, it also contributes.

Now the stones themselves are made of calcium phosphate, some smaller amounts of magnesium, ammonium and other potassiums. We also know that bacterial biofilms and the bacteria themselves may also serve as an anitis and also food debris may also get involved in this area.

The whole thing is that saliva is not moving and a whole bunch of debris and calcium and everything is getting together. And what ends up happening is it starts to coalesce into a stone. Now, those are the most commonly accepted pathogenesis and ideas as to why they develop. But we also know there are some patient risk factors like hypovolemia, using diuretics and being on anticholinergic medications that give you dry mouth.

Trauma to the area can disrupt the ducts and cause stasis. Patients who have gout, who smoke cigarettes or use dip, or now with Zins. And we've also found that people with really bad periodontal disease also develop these stones. And what's ironic is that patients who also have kidney stones are more likely to also get salivary stones.

So, so far this is not sounding too great, but here's some good news. We actually have found that the incidence of this is pretty low. In fact, most studies have found about a 1% incidence in autopsy studies. Patients who present with clinically symptomatic stones are super low and they're under 1%. That's a good thing. From a demographic standpoint, men are more likely to develop this and it's usually somewhere in the ages of 30 to 60, so the patient's age doesn't play much role.

Now, what we do know is that most stones are unilateral, and only 3, maybe even 4% of people come in with bilateral stones. And my patients always ask me, hey, I got my stone on the right. Is the right more favored? It turns out the stones occur equally on the right and left side. It's all about risk factors and the pathogenesis, which we, like I said, don't fully understand.

So what's the million dollar question? Which gland is more affected? And if you're asking the boards, it's going to be the submandibular glands. And it's actually the most common. 80 to 90% of these stones will occur there. Then the next most common is going to be in the parotid glands, which are around 6 to 20%. And then those minor glands we talked about, like sublinguals, only 1 to 2% of the time. Now, most of your patients, like I said, may not know they have one. But sialolithiasis, when it does become symptomatic,

presents with pain and swelling in the involved gland and in the soft tissues of that area. When they eat something sour or they're going to anticipate eating something, it actually causes more pain because those glands are getting ready to swell and contract and the stones in the duct are preventing that, which causes back pressure and pain.

Essentially, it's the world's worst traffic jam of saliva. Now also, we have to realize that if a patient comes in with systemic symptoms, like the pain is continuing to get worse, there's erythema of the soft tissues and even a fever, then there may be a superimposed infection in this area as well. So how do you make this diagnosis? Well, it turns out you don't really need to do much except for a good physical exam. Have the patient gently relax their mouth and palpate the floor of the mouth along the posterior to anterior direction along Wharton's duct

you may actually feel the stone there along the duct's angle or you may even see it near the frenulum of the tongue when it's the submandibular gland that's going to be your most common location if it's the parotid then you're just going to palpate the buccal mucosa along the opening of stinson's duct and you may feel the stone there usually next to the second upper molar now here's what's going to happen while you're palpating

If the gland is working fine, it's going to feel spongy and kind of like gum. During palpation, you may also notice some clear saliva coming out, and that's a good thing. If you don't, then you have to also start thinking there's an obstruction. If you see purulence coming out, then there's a secondary infection. Now at this point, if your patient's presentation is pretty classical, you can go ahead and say that's the most likely diagnosis. They have a sialolithiasis.

But if the presentation is not clear or it's not slam dunk diagnosis and you're not 100% sure, the most accurate test is a non-contrast CT scan of the face, head, and soft tissues of the neck. The stone will have enough calcium in it to light up like a Christmas tree. And then you can go ahead and make the diagnosis that way. But remember, the CT scan is not needed to make the diagnosis. You yourself with history and physical is more than enough. It's just a tiebreaker.

Now at this point you've made the diagnosis, the next step is to help your patient feel better. The first thing you're going to do is tell them discontinue medications that are going to dry out their mouth like diphenhydramine or even amitriptyline which needs to be tapered off.

For the pain, they can then use NSAIDs sparingly, not too often because you don't want them to get a stomach ulcer. And then after that, it's conservative management. You want them to stay well hydrated, apply warm compresses and moist heat to the area. And then of course, massaging the gland helps push saliva flow forward and helps the stone kind of gently pass.

In addition to that, you're going to send them to the candy store. That's right, this is not a 50 cent song, but you're going to tell them to go ahead and buy tart or hard candies such as lemon drops and tell them to use them throughout the day. Initially, it's going to be a little bit painful, but that's going to actually help them with expressing more of the saliva and getting the stone out. And some patients have even said they felt the stone pop out and they had to spit it out.

Now, if you notice purulence coming out of the duct or they're having more pain or fever, you also want to give them some anti-staph antibiotics like cefalexin. You can go ahead and do this for about five to seven days and monitor their treatments. If they're not getting better, then you want to bring them back, broaden the coverage, get a CT scan, and then consider referring them to your colleagues at the ENT service. But most patients with just some conservative care, some hard, soft candies, and improving on those risk factors get better.

And with that, ladies and gentlemen, brings us to the end of another great episode on It's the Small Things, Salivary Glandstones. I'll see you next week where we talk about some other different small things that can cause all kinds of problems for your patients. I'm Dr. Naked Sanpal. I'll see you next week.