Did you know that a lung abscess can look like lung cancer on an X-ray? Lung abscesses come from bacterial infections rather than cancer, but on an X-ray, both might look like small masses on your lungs. Here, we’ll discuss what a lung abscess is and how doctors can distinguish it from lung cancer.

What Is a Lung Abscess?

A lung abscess is an enclosed volFume of pus in the lungs. On an X-ray, it might look like a hollow mass. Lung abscesses can be difficult to treat, but they’re not cancerous.

If you have a lung abscess for less than six weeks, it’s described as acute. Chronic lung abscesses are abscesses you’ve had for more than six weeks.

Causes

Both bacterial and nonbacterial infections in the lungs can cause abscesses. The pathogen (disease-causing organism) can reach the lung tissue in different ways.

Have you ever had the feeling of something going down the wrong pipe? This can happen when saliva or fluid accidentally enters your airway. If the saliva contains bacteria, it can cause an infection in the lungs, leading to a lung abscess. Most lung abscesses develop as a complication of inhaling a foreign substance, which causes localized pneumonia, followed by tissue death and cavity (hollow space) formation.

Abscesses can also form if an infected blood clot moves to the lungs. This process is rare, however.

Risk Factors

People who have a weakened immune system are more likely to develop lung abscesses. This is because they can’t fight off the bacteria on their own.

Conditions that make people more likely to accidentally allow spit to get into their airways also raise the likelihood of lung abscesses. These conditions include:

• Seizures
• Other problems with nervous system function
• Overconsumption of alcohol

Additionally, a blockage in the lung, such as a tumor, can put you at risk of developing a lung abscess. This is because a blockage can make it harder for you to cough up any infected sputum (mucus and saliva) and clear it from your lungs.

Symptoms

The symptoms of a lung abscess are similar to those of pneumonia, including:

• Chills
• Productive cough (often with a bad smell or taste)
• Shortness of breath
• Tiredness
• Fever
• Lack of hunger
• Chest pain
• Weight loss

You may also feel sweaty during the night.

Are Lung Abscesses and Lung Cancer Related?

Lung cancer can create conditions in your body that make it more likely for you to develop a lung abscess. This increased risk is driven by a few factors.

Many cancer treatments weaken the immune system. When you have a weakened immune system, you’re more likely to develop lung abscesses.

Another way lung cancer could put you at risk is through potential airway blockages. If your tumor blocks part of your airway, it may be hard to cough out infected material. Clearing infected sputum from your airway is an important part of preventing lung abscesses.

Certain medications for non-small cell lung cancer, such as pembrolizumab (Keytruda), can cause pneumonia for some people. Pneumonia can cause lung abscesses, so these medications may increase your risk.

Is It Possible To Confuse a Lung Abscess With Lung Cancer?

A lung abscess could be confused with lung cancer. The conditions can have similar symptoms and can look the same in X-ray images. Abscesses are usually hollow, whereas tumors are usually solid. However, a small percentage of lung cancers are hollow or can become infected, and abscesses can be solid in the early stages. Also, endobronchial cancer, a rare tumor in the lungs’ airways, can cause a lung abscess. Because of the potential for confusion, your doctor will do a thorough medical workup to make sure you have the right diagnosis.

Diagnosing Lung Abscess vs. Lung Cancer

Diagnosing a lung abscess and differentiating it from lung cancer may take a few steps. Your doctor will want to get images of your lungs to look for unusual spots. They’ll also want to test fluid from your lungs to see what types of cells it contains and whether there’s an infection.

X-Ray

A chest X-ray can produce images of your bones and soft tissue. These scans are easy to access and can often help distinguish between a lung abscess (typically hollow) and lung cancer (usually solid). However, an X-ray is only two-dimensional, so it may be harder to read for an accurate diagnosis. When lungs are filled with fluid, as happens with pneumonia, it’s harder to see structures.

CT Scan

A CT scan is another way your doctor can get images of your chest. CT scans also use X-rays to show your bones and soft tissue, but they can take pictures at different depths to create a three-dimensional image. Sometimes, doctors trying to determine if there is a lung abscess need images with additional depth to tell if what they’re looking at is hollow and filled with pus rather than a solid mass.

Sputum Tests

Your doctor may test your sputum to see what’s causing your symptoms. If they suspect you have an abscess, they’ll check if your sputum contains bacteria. They’ll use the sample sputum to grow the bacteria and see which antibiotics it responds to. Although it may be hard to pinpoint which bacteria are causing the abscess, your doctor may be able to rule out some types. Infected sputum is green or yellow and has an odor or can be tinged with blood. Those characteristics wouldn’t be expected for lung cancer without an infection.

If your doctor suspects you have lung cancer, they may look at your sputum under a microscope to see if there are cancerous cells, which wouldn’t be expected in an abscess alone (no cancer).

Bronchoscopy

A bronchoscopy is a procedure in which your doctor puts a thin, flexible camera down your airway to see your lungs. This is usually done to get a sample directly from the mass or your lungs. The collected sample can then be looked at under a microscope to see if it contains bacteria or cancer cells. Similarly to sputum tests, these tests can help rule out certain types of bacteria. Doctors usually perform a bronchoscopy only if you may have a blockage, you have a weak immune system, or antibiotics aren’t working.

Talk to Your Doctor

If you have any new or worsening symptoms, be sure to talk with your doctor. Addressing symptoms of a possible lung abscess quickly is important for the best outcome. Your doctor will be able to perform the appropriate tests to find out what’s causing your symptoms so that you can get the proper treatment.

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