As Vaping-Related Cases Grow, Lung Pathologists Seek Visual Signs
As the number of vaping-related illnesses continues to climb in the U.S., pathologists who diagnose lung injuries as part of a larger healthcare team, say it’s not easy to see the signs of vaping under a microscope.
But that may be changing as scientists identify the visual cues common in patient specimens, whether or not they are forthcoming about their vaping habits. A new study published in the New England Journal of Medicine (NEJM) and reported in The New York Times compared vaping related lung damage to the same type of damage caused by chemical burns.
Moises Velez, M.D. is the director of the Thoracic Pathology subspecialty service at the University of Rochester Medical Center. He and fellow cytopathologists, Tanupriya Agrawal, M.D., Ph.D. and Ellen Giampoli, M.D. shared more about the ways in which vaping is showing up in everyday diagnoses, and how recognizing the signs can get patients help quicker.
What exactly does a thoracic pathologist do, and what do they look for?
Normal lung cells as seen under a microscope after staining, at 20x magnification.
Visible inflammation in lung cells of a patient known to have vaped (magnified at 40x).
Normal lung fluid magnified 40x.
Lung fluid (magnified 60x) of a patient with a history of vaping. The lipid or oil in the cells stain red with Oil Red O. This is presumably caused by vaping or inhaling an aerosolized oily substance.
Velez: A thoracic pathologist is a specialized doctor that diagnoses diseases of the thorax, or chest cavity, by looking at tissue or fluid specimens under a microscope. Hundreds of disease which fall into this category.
Have you ever encountered a case in which a patient had lung damage due to vaping?
Agrawal: To date, I have received four bronchoalveolar fluid specimens (BAL) that came from patients with a history of vaping. Each patient presented with signs of respiratory failure.
In recent months, I had a teenage patient who was admitted to the ED with respiratory failure. They had a history of marijuana use and couldn’t remember what they inhaled the day before, but had vaped a few months before.
What is known from the literature is that vaping can present acutely and up to 90 days. So if someone has vaped in the last 90 days, it can present later. Because of the history for vaping, the patient was treated with steroids and antibiotics and later discharged.
Why is it difficult to know what damage is caused by vaping?
Velez: Recent literature in the NEJM reported patterns of lung injury such as diffuse alveolar damage, organizing pneumonia, granulomatous pneumonitis and foamy macrophages in patients with a history of vaping. We know these patterns of lung injuries described are not specific to any disease process.
For example, they can also be seen in an infection, sepsis, drug toxicity, toxic inhalation, and collagen vascular disease to name a few. If the history of vaping is known, Oil Red O may be performed to identify lipid in macrophages. Knowing the clinical history is the key make the association of vaping and lung injury.
Aren’t there other methods, like CT images, to detect a lung injury that could be vaping-related?
Velez: Clinicians suspect lung injury if someone has been inhaling something recently (such as e-cigarette vapor) and they develop shortness of breath and come to the ED. Then they may undergo a chest CT. The radiologic findings are not specific and show patterns that can correlate with eosinophilic pneumonia, diffuse alveolar damage organizing pneumonia and lipoid pneumonia. The history of inhalation coupled with the radiologic and histologic evidence of the lung injury, means you can suspect this was due to vaping.
In other words, a pathologist can probably tell a person is sick because of vaping, based on what they see under the microscope, but unless you know from the patient’s doctor that they vape, you can’t link the two?
Agrawal: Correct. If we are not provided with the patient’s history, it’s just an acute lung injury for us. Maybe the patient has an infection, but unless a history or clinical report is provided or there is some clinical suspicion, we as pathologists cannot make a determination.
Do you think patients don’t want to disclose that they’ve vaped for fear of stigma, or that they’ll be punished for doing something illegal (especially if they vape an illegal substance like marijuana)?
Velez: It’s uncertain if vaping carries any stigma at all, but it’s possible that youth may conceal their habits. There are over 2,000 flavors of vaping cartridges, so it’s enticing. The nicotine vaping cartridges also contain as much nicotine as a pack of cigarettes. None of this is FDA-regulated.
Agrawal: With teenagers especially, they want to experiment with vaping and mixing edible oils so nobody knows exactly what they’re inhaling, how it’s being transformed as it goes into the lungs. There is no research out yet on this.
Some see vaping as an epidemic. What’s one practical way clinicians can help fight it?
Giampoli: Our physicians and ER docs on the front lines need to get nosy and ask patients if they vape. At the moment there’s nothing specific for us to identify it with until we see more cases and can identify patterns in what we’re looking for.
Our whole job is finding patterns with the information we have. We will be able to recognize these cases faster, pick up these connections quicker, and hopefully be able to help our clinicians help these patients much more quickly.
Bethany Bushen | 11/21/2019
