Benign Nodules and Lung Malignancy

00:01 So some common benign nodules are granulomas or hamartomas.

00:05 Those are really the two most common that are seen within the lung.

00:08 A granuloma is an old healed lesion that's usually a result of either a prior TB infection or histoplasmosis infection.

00:15 Often these are calcified and they're usually small less than about a centimeter in size.

00:21 So this is an example of a granuloma.

00:23 You can see here a calcified nodule in the left lung, and this is very typical example of what a granuloma would look like.

00:31 So hamartoma is an area of abnormally organized lung tissue that can contain fat or calcifications, classically it contains what are called popcorn calcification.

00:42 So you can see an example of a couple of hamartomas here in the right lower lobe that contain this kind of irregular popcorn calcification.

00:51 There are several different types of lung malignancy and we'll go over general characteristics of each one.

00:57 So squamous cell carcinoma is centrally located, it demonstrates rapid growth, and it often results in bronchial obstruction or post obstructive pneumonitis or atelectasis.

01:08 Small cell carcinoma is also centrally located and it can represent variable growth.

01:13 This can often cause paraneoplastic syndromes because it contains neurosecretory contents that can be secreted.

01:19 Adenocarcinomas are usually more peripherally located and they are very slow growing.

01:25 And large cell carcinomas are also peripherally located but they demonstrate rapid growth.

01:30 Large cell carcinomas are really a diagnosis of exclusion.

01:33 When you do see a lung malignancy, it's often difficult to identify exactly what it is.

01:37 We can kind of guess based on these characteristics which one of these it could be but the patient really does need a biopsy to prove that.

01:45 So this is just a diagram again showing you the general location and size of each of these malignancies.

01:51 So how can you differentiate between a mass or pneumonia? Masses can occasionally have a similar appearance to pneumonia, they both appear as an area of consolidation.

02:01 Patients present with clinical and imaging features of pneumonia but high risk factors of malignancy and that can really confuse the diagnosis.

02:10 What you wanna do is obtain a follow-up radiograph about two weeks after the completion of antibiotic therapy in a patient that's presenting with signs of pneumonia but you're unsure of whether there's underlying mass.

02:21 And this will help you ensure that there's full resolution of the area of consolidation.

02:25 You really have to wait about 2 weeks after the completion of the antibiotics because imaging findings of pneumonia can kind of lag behind, and they may persist after the clinical symptoms resolve.

02:36 So what happens if you see multiple nodules? Generally, multiple nodules can represent benign granulomas.

02:42 However, they can also be malignant and usually when there multiple, they're often metastases. So let's take a look at this case.

02:52 This is a 65-year-old smoker that's presenting with cough.

02:56 This is the case that we started off with at the beginning.

02:59 So we said that there are abnormalities in the left upper lobe, and this actually looks like an area of consolidation.

03:05 So this patient was treated with a course of antibiotics followed by repeat radiograph performed about two weeks after completion of treatment because the patient had a smoking history and the patient was older, so somewhat high risk for a malignancy.

03:19 This was performed about a month later, so two weeks after the course of antibiotics.

03:26 So do you see any abnormalities on this' Here's a closer look.

03:36 So you can see that the area of consolidation has actually resolved.

03:38 So we no longer see that.

03:40 However, let's take a good look at the lung bases.

03:43 There's actually a very subtle nodule that's seen at the right base.

03:48 This was actually not identified because it is very subtle.

03:52 The patient ended up presenting again about 2 years later with a cough.

03:57 So what do you see now? So this patient actually has this persistent nodule in the right lower lobe, which does appear a little bit more prominent now.

04:13 In addition, there's a nodule in the left upper lobe in the area of the previous pneumonia.

04:19 So this is an example of a lung malignancy.

04:23 This patient ended up having a CT scan to take a better look at the nodules and you can see in the right lower lobe, there's a spiculated nodule, there are bilateral pleural effusions, and then in the left upper lobe there's a much larger irregular mass, and so this patient presented with a lung malignancy two years after that very subtle nodule was seen in the right lower lobe.

04:46 Here's another example, let's take a look at this, what do you see here? So this patient has bilateral lower lobe nodules.

05:00 They're symmetric, they're the same size, they're the same location, so what could this represent? And is there a way to prove what this really is? So what you wanna do is place radiopaque BBs to mark the nipples and then re-image. When this is done you can see that the BBs overlap where the nodules are. So nipples can actually cause nodular shadows within the lungs, so if you see bilateral symmetric nodules in the lower lobes, this would be a great first step as to place BBs on the nipples to see if the nodules are caused by nipple shadows in with this patient, they are.

05:41 So we've gone over the different types of lung nodules that you can see.

05:44 We've reviewed some of the characteristics of benign and malignant nodules.

05:47 And we've gone over the importance of doing a follow-up radiograph in a patient that's presenting with pneumonia but it has high risk factors for malignancy.