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Nasal polyps

Created by Jeff Otjen.

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Video transcript

- [Voiceover] What are nasal polyps? The short answer is that a nasal polyp is an overgrowth of tissue inside your nose. But to better understand exactly what is going on, we should talk about what's supposed to be inside your nose. Normally, the inside of your nose is lined by this pink, squishy tissue known as nasal mucosa. This tends to be a paper-thin layer of cells that lines the majority of the inside of your nose, although there are some areas that can be quite a bit thicker. In fact, over the course of a day, some areas of nasal mucosa will swell and de-swell, and sometimes you can actually feel that happening. But what happens if something goes wrong? Let's say, for instance, that this particular nose has allergies to pollen. And here I'm drawing in a couple of pollen grains, quite a bit larger than they actually are, as they're getting inhaled up into the nose. In people with allergic rhinitis, this sets off a chain reaction of inflammation inside the nose, and one particular thing that can happen, in the setting of chronic allergic rhinitis, is that that nasal mucosa becomes so irritated that it starts to grow and expand. And, in fact, chronic allergic rhinitis is the number one cause of nasal polyps. So, let's say after a long time of being inflamed, this particular patch right here decides to become a little bit bigger and a little bit thicker. First it may form a little bump, but over time that bump can become bigger, and it can become bigger and bigger and bigger, until it's quite large. Now, it may seem that this is acting a little bit like a tumor, and it is a sort of neoplasm, but this isn't a malignant process. It tends to just hang out in the nose, but that's not exactly a good thing. The nose is a sensitive area. There's a lot of things that need to happen. There's lots of things that you may not even realize drain into your nose. For instance, your sinuses all live right next to your nose, and if a large polyp, like this one, decides to get in the way of the outlet of those sinuses, that can cause further problems with chronic sinusitis. So, a couple more facts about nasal polyps before we go on to some real-world examples. These are actually fairly common things to happen, at least in adults. It's one of the more common intranasal growths that occur, however, if you see it in kids, that's much more uncommon. In fact, in kids it's mostly seen only in patients which have cystic fibrosis. Another fun fact to know about nasal polyps. There's an association with other types of allergic disease, but in particular there's an association with the combination of asthma and a specific allergy to aspirin. Some people will call the combination of asthma and allergy to aspirin and nasal polyps an allergic triad. So, let's go ahead and look at those real-world examples. Now, the first thing to go over is a little bit of normal anatomy. Here, I've got pulled up a single patient's CAT scan, but I'd like to point out a few things before we go on to a patient who has nasal polyps. The image on the left is a coronal image, and what that means is basically it looks like you're looking at the patient's face straight on, and you can kind of see that. So, I'll point out a few structures here. First, we can see the eyes, one on each side. We have the tongue down here in the mouth. You can see a few teeth adjacent to the tongue. But we're going to be focused in particular on this area in here, and this is the patient's nasal cavity and sinuses. So, these larger spaces that are filled in with black, that black is air. These are the maxillary sinuses. This straight thing running down the center of the patient's nose is the septum, and then we have these little curly-cue things that hang off the wall of the maxillary sinus, and these are called turbinates. Up here at the top of the nasal cavity, these air-filled spaces are the ethmoid sinuses, also called the ethmoid air cells. All of these structures inside the nose are actually lined by that mucosa that we were talking about earlier. So, I'll draw in here. You can actually not really even see it when it's as thin as it's supposed to be, but it gets thicker around the turbinates, and you can see some of that here, and all of this pink that I'm drawing in here, that's mucosa. Now, this image over here is an axial image, and this axial image is basically what we would get if we took a slice that ran about right here through this patient's head and looked at only that slice. You can see some of the same structures. Here we have a turbinate. Here we have the nasal septum. Here we have a maxillary sinus, and up at the front here, we have the patient's nose. So, now that we have a pretty good grasp of what the normal anatomy is, let's go on to some abnormal anatomy. Remember, we talked about that nasal mucosa as it was getting inflamed and generating this hyperplastic tissue that we called the polyp. Well, here's a CAT scan, the same coronal and axial types of images through a patient who actually has a nasal polyp. You'll notice some differences with the prior scan. First off, the maxillary sinus on this patient's right side is completely filled in with material here. It's hard to know exactly what that material is. I'll shade it in over on this axial image as well. Some of it might be thickened mucosa. Some of it might be mucus. Some of it might actually be part of a polyp. And here, right up next to this patient's septum, you can see this tissue that wasn't in the last patient, and this tissue is actually a part of a polyp. You can see it on the coronal view here, and you can see a portion of it here on the axial view as well. In fact, the patient probably has another one on this side over here. This one is smaller and not causing any problems. But this polyp, centered where it is, is actually obstructing the outflow to that maxillary sinus on the right side, and when that happens, mucus will fill up, things will get inflamed, infections tend to occur, and that's one of the bigger problems with nasal polyposis. Mass effect just due to the presence of the actual tissue itself causes obstruction to things like sinuses, to the tear ducts that drain into the nose, and to the eustachian tubes which drain the ears. The tear ducts are up here at the front of the nose, these are also called nasolacrimal ducts, and the eustachian tube that runs out to the nose is located at the back. So, you can see if this particular polyp gets any bigger, this patient runs the risk of obstructing that eustachian tube and causing problems with his middle ear. Going back to our cartoon, here we've drawn a nasal polyp, similar to the one that we saw on our patient's CAT scan, but that's not the only place they can occur. They can occur up at the front of the nose here. They can occur down at the back of the nose here. They can occur at one part of the nose and then extend in a tubular fashion to another part of the nose. Every polyp is a little bit different, and most of the symptoms from these polyps will depend on exactly where they are. So, what can we do about it? Well, there's a few things that you should do. The first thing is you should always try and get rid of what's causing the inflammation in the first place. In most cases, that means treat the allergy. Sometimes that only partially works or might not work at all. In that case, your second line of therapy is often times surgery. Now, while both of these treatments are good, there is a chance with either one of them that nasal polyps can recur. And some patients may undergo long treatments to get their inflammation under control or have multiple surgeries to get rid of the polyps.