Clinicians Think Cancer, but Cessation of E-Cigarette Use Vaporizes the Diagnosis

The patient reported that she converted from smoking cigarettes (20 pack-years) to vaping (38mg/mL, 10mL per week), 20 months prior to her referral to the clinic. Six weeks after the initial CT scan, a follow-up scan showed a marked regression of the nodules, and a further CT scan 5 months later displayed complete regression of all lung nodules.

The patient stated that she had stopped vaping after her first referral, as she presumed a diagnosis of cancer. To test whether the nodules initially identified could have been induced by her vaping, the lung biopsy specimen was re-examined. An area was detected with multinucleated giant cells, suggesting a foreign body reaction to a nonbirefringent material. This material was consistent with glycerin-based oils found in droplets from e-cigarette vapor, strongly suggesting that e-cigarettes may cause an inflammation in the lungs that can cause nodules which imitate metastatic cancer.


A case-controlled study has shown short-term vaping in healthy smokers can induce adverse physiological (although asymptomatic) effects similar to those seen in tobacco smoking. A self-reporting study found that the most common adverse events affected the respiratory system (J Med Internet Res. 2013;15(4):e59). Eosinophilic pneumonitis and exogenous lipoid pneumonia have both been tied to e-cigarette use, though the long-term effects of vaping on pulmonary function remain unknown, heightening a need for further research.

The authors of this report note how their initial hypothesis of malignant disease, followed by the multiple testing procedures, caused considerable undue stress to the patient. Their finding of an association between asymptomatic inflammation in the lungs and use of e-cigarettes in this case may act as a diagnostic aid to clinicians in the future.