Pulmonary Nodule: The incidentaloma

Nov 14, 2013

What do lung nodules have to do with emergency medicine? Weʼd like to see ourselves as full time resuscitationists and while thatʼs one of our master skills, much of our job involves  taking care of non-critical patients and, even more so, having conversations with patients and their families. But arenʼt pulmonary nodules someone elseʼs problem, like the pulmonologist? Yes, and no. The pulmonologist is going to manage things in the long term, but the overwhelming majority of nodules are going to be incidental findings that land in your lap.

Clinical scenario:

You get a phone call from the radiologist on a CT chest, “Thereʼs no PE or sign of dissection, but thereʼs a 5mm non-calcified pulmonary nodule in the right upper lobe” What does that mean? Do you need to pay attention to it? Can you ignore it? What do you tell the patient?

The conversation often goes something like this, “Good news Mr. Jones, we donʼt see a blood clot and, oh by the way, the radiologist saw a small nodule.” For you, someone who is used to getting reports of an incidental pulmonary nodule, itʼs no big deal. For the patient, what they heard is, “You have cancer.” That may sound like hyperbole, but itʼs most patientsʼ first reaction.

Mr. Jones may or may not have cancer and Mr. Jones may or may not ask you questions. We donʼt want to do is to induce fear in the patient by our ignorance but we also donʼt want to dismiss the findings and ignore a possible malignancy.

Is this a bad nodule?

1. Assessing risk and determining a long term follow-up/treatment plan for a patientʼs pulmonary nodule is beyond our scope of practice. But there are some background points that may help in your conversation.
2. Around 5% of pulmonary nodules turn out to be cancer.
3. The bigger the nodule, the higher the risk of malignancy. In smokers risk of a 5mm nodule being malignant is  1/500, 10 mm is 1 in 50, and  20mm is 1 in 10.
4. Pulmonary nodules are common- half of smokers over 50 have at least one nodule. Up to 150,000 patients in the United States have a pulmonary nodule diagnosed each year.
5. Young patients (<35) have a very low incidence of lung cancer (<1%)
6. Complete calcification in a small nodule suggests benign etiology. When your radiologist says, “A 4mm completely calcified nodule in the right lower lobe,” thatʼs code for, “probably benign, but clinical correlation recommended.”
7. The false positive rate for chest CT lung nodules varies by geographic location. The midwest has the highest false positive rate because of granulomatous disease.
8. Risk factors: Itʼs no secret that non-smokers can get lung cancer, but smokers have 10 times the lung cancer risk of non-smokers. There are other risk factors like asbestos, radon and genetics, but smoking is by far the most heavily weighted. Also, the older the patient, the more likely a nodule is malignant.

Who needs follow-up and when should they get it?

This comes down to risk and benefit. Risk  that this nodule is malignant, the benefit of follow up imaging versus the risk of extra radiation, unnecessary biopsies, surgeries, anxiety, and medical bills. While it’s not well known in emergency medicine,  The Fleischner Society is a group in radiology that develops an evidence based consensus guideline on how to follow up  pulmonary nodules.

 

Fleischner Criteria

 

Nodule size and patient risk factors are the principle elements that determine timing and type of follow-up study needed. There are two main pieces of the Fleischner Criteria that are germane to emergency providers:

1. Almost all pulmonary nodules are going to need a follow up CT scan. When that happens depends on risk factors and nodule size.
2. Low risk (meaning a minimal or absent history of smoking and other known risk factors) patients with small nodules ≤4 mm do not need follow up.

These guidelines suggest that the likelihood of a small (≤4mm) nodule being cancer in low risk patient is so low that no further follow up is needed. Will some of these nodules turn out to be cancer? Yes, but striving for a zero miss rate in this group is not risk-benefit favorable. The likelihood of the patient having negative sequelae (radiation, unnecessary biopsy, surgery, financial hardship) is greater than the chance of the nodule being cancerous. Itʼs analogous to striving for a 0% MI miss rate. Cost far outweighs benefit.

The Other Side of the Fleischner Coin

Not everyone follows the Fleischner guidelines.  Some radiologists recommend follow-up imaging, or at least discussion, for every patient with a newly diagnosed nodule. Pulmonary nodules are a complex topic with multiple factors and variables that dictate the best course of action (or no action). These patients need follow up, preferably with a pulmonologist, to discuss risk level and decide what to do next. When weʼre talking about a one millimeter difference dictating a follow up scan versus doing nothing, one of my colleagues who is a chest radiologist, has this to say, “Depending on how much coffee Iʼve had to drink, I can measure the same nodule 20 times and have it be different every time, so trying to make separate recommendations for nodules that are ≤4mm or 4-6mm is silly to me. “

Tips for communicating with patients

1. Emphasize that pulmonary nodules are a common finding but donʼt appear unconcerned. While you are trying to demystify and normalize the finding, avoid acting as if itʼs ʻnothing at allʼ.
2.  Give simple explanations. Avoid confusing medical terminology
3.  Itʼs OK to mention the possibility of cancer, even if itʼs remote. Donʼt avoid the elephant in the room (cancer). Your patient will probably start out with the idea that their nodule is cancer and prefer to have an honest conversation about it.
4.  You will not know all of the answers but that wonʼt stop them from asking questions.
5.  There is no correlation with the patientʼs actual risk of cancer and their level of concern. A 2 mm nodule in a 30 year old can evoke as much fear as a 2 cm nodule in a 60 year old smoker.
6.  Reassure your patients they are not alone. Nodules are a common incidental finding and, after the patient leaves the the ED, a pulmonologist, PCP, etc will help guide them along the way.
7.  If you donʼt think news of a nodule impacts your patientʼs psyche, here is a quote from a patient with a newly diagnosed nodule, not diagnosed cancer, but a nodule, “I actually gave notice at my job ... and spend more time with my kids. I donʼt know whatʼs going to happen and I donʼt want to miss anymore.”

What are you going to say to the patient?

Here are some example scripts for delivering the news of a newly diagnosed nodule...

“Mr Jones, good news, there's no blood clot. The radiologist did mention that he saw a small spot on your lung. The medical term for it is a nodule. It's 5mm, which is about half the width of your little finger or the size of a pea. We see these all the time and 95% turn out to be completely harmless so I don't want you to lose any sleep over this. You will, however need to make sure someone takes a look at this again with a CAT scan to make sure it's not growing. Iʼm going to refer your to our pulmonologist, a lung specialist, who is an expert in lung nodules and will help guide you the rest of the way.”

Maybe Mr. Jones is low risk.... “The chance of this nodule being anything serious is extremely low. The nodule is small, you donʼt smoke and youʼre young. The risk isnʼt zero, but itʼs pretty close. I still think you should follow up to discuss all of the options, but in all likelihood, this will not cause you any problems.”

Bottom line:

The overwhelming majority of pulmonary nodules are benign. The bigger they are, the higher the chance of malignancy. There is debate as to whether a very small lung nodule in a low risk patient needs follow up at all. Should an emergency provider make the call that no follow up is needed? I think there is too much uncertainty in sorting out all of the variables that go into risk factor assessment. I refer all patients with newly diagnosed nodules for follow up, risk stratification, and further discussion with their PCP or a pulmonologist.

Patients almost always have questions about the significance of their newly diagnosed pulmonary nodule. What they really want to know is if they have cancer. You canʼt know that looking by at a nodule one time. For a small nodule, itʼs about how it grows (or doesnʼt) on repeat studies. The things that make cancer more likely and follow up more urgent include size >4mm, age over 35, history of smoking, and nodules that are not completely calcified.

In the end, it may be cancer, but chances are, your patient is going to be just fine.

 

Bonus Section... Even more information about pulmonary nodules!

Historic Guidelines

Historically, all patients with non-calcified nodules were recommended to get follow-up chest CTs for 2 years. This was based on the pre helical CT era when most pulmonary nodules were found on chest x-ray. By the time a nodule is seen on CXR, itʼs often big. The old ACCP recommendation for indeterminate solitary nodules was follow up CT at 3-, 6-, 12-, and 24 months. Thatʼs five chest CTs (including the original study), no matter what. When you consider that upwards of 51% of smokers over age 50 have pulmonary nodules, that is a lot of negative CT scans, radiation, unnecessary biopsies, surgeries, anxiety, and money spent. With our ability to diagnose smaller nodules, we needed to change our thinking about what to do with them. Thatʼs what the Fleischner recommendations addressed. Itʼs not one size fits all.

Does it make a difference if the nodule is measured on CT or Chest X-Ray?

These measurements apply only to CT scans. CXR is too inaccurate. The work-up for nodules found on CXR varies depending on the scenario. The first step is to try to get old films to see how long it's been there. If no old films are available, depending on nodule features and clinical story, the patient needs either a CT scan or a short-term follow up CXR (4-6 weeks) to see if it persists. Sometimes it's tough to tell if a nodule is calcified on CXR. If it is obviously calcified, it doesn't need any follow-up.

Calcification

What does calcification in a nodule suggest? Calcification in a small nodule suggests benign etiology. Mostly. A partially calcified nodule or one with eccentric calcification needs followup. Malignancies, like scar carcinomas (from old granulomas), and mucinous adenocarcinomas can have small calcifications.

Appearance

How should you think about terms like ground glass, semi-solid, and solid? Does appearance make a difference when it comes to determining nodule behavior?

In general...

• Ground glass - grow slowly
• Solid nodules- grow quickly
• Party solid, which is between ground glass and solid- medium growth rate (itʼs also associated with adenocarcinoma)

Caveats-

1. Known malignancy gets a different workup. A history of cancer means that nodule is more likely to be malignant.
2. Young patients (<35) have a very low incidence of lung cancer (<1%). The radiation from multiple follow up CTs exposes them to greater risk than older patients
3. In the setting of unexplained fever, nodular densities may represent infection

References

1) MacMahon, Heber, et al. "Guidelines for Management of Small Pulmonary Nodules Detected on CT Scans: A Statement from the Fleischner Society1."Radiology 237.2 (2005): 395-400.

2) Wiener, Renda Soylemez, et al. "What Do You Mean, a Spot? Physician Patient Communication About Lung NodulesA Qualitative Analysis of Patients’ Reactions to Discussions With Their Physicians About Pulmonary Nodules."CHEST Journal 143.3 (2013): 672-677.

3) Silvestri, Gerard A. "Lumps, Bumps, Spots, and ShadowsSolitary Pulmonary NoduleThe Scary World of the Solitary Pulmonary Nodule." CHEST Journal143.3 (2013): 592-594.

4) Mehta, Atul C., and Peter J. Mazzone. "An Attempt to Reach the Galaxy of the Pulmonary Nodules." American journal of respiratory and critical care medicine188.3 (2013): 264-265. 5) Slatore, Christopher G., et al. "What the Heck Is a “Nodule”? A Qualitative Study of Veterans with Pulmonary Nodules." Annals of the American Thoracic Society 10.4 (2013): 330-335.

6) Patel, Vishal K., et al. "A practical algorithmic approach to the diagnosis and management of solitary pulmonary nodules: part 1: radiologic characteristics and imaging modalities." Chest 143.3 (2013): 825-839. 7) Patel, Vishal K., et al. "A practical algorithmic approach to the diagnosis and management of solitary pulmonary nodules: part 2: pretest probability and algorithm." Chest 143.3 (2013): 840-846.

8) Shiau, Maria C., Elie Portnoy, and Stuart M. Garay. "Management of solitary pulmonary nodules." Clinically Oriented Pulmonary Imaging. Humana Press, 2012. 19-27. 9) Masciocchi, Mark, Brent Wagner, and Benjamin Lloyd. "Quality review: Fleischner criteria adherence by radiologists in a large community hospital."Journal of the American College of Radiology 9.5 (2012): 336-339.

10) Wiener, Renda Soylemez, et al. "‘The thing is not knowing’: patients' perspectives on surveillance of indeterminate pulmonary nodule." Health Expectations (2012).

11) McWilliams, Annette, et al. “Probability of Cancer in Pulmonary Nodules Detected on First Screening CT.” NEJM 369:10 (2013): 910-919.