Transient asymptomatic pulmonary opacities in a patient with MET exon 14 skipping non‐small cell lung cancer: A case report

Mesenchymal epithelial transition factor receptor (MET) tyrosine kinase inhibitors (MET‐TKIs) have been approved for the treatment of non‐small cell lung cancers with MET exon 14 skipping mutations. Transient asymptomatic pulmonary opacities (TAPOs) associated with epidermal growth factor receptor (EGFR)‐TKIs have been reported. Here, we report a case wherein ground‐glass opacities (GGOs) appeared during the course of treatment with tepotinib, a MET‐TKI, but spontaneously resolved with drug withdrawal, after which treatment was resumed with a reduced dose. Although there have been no reports of TAPOs with MET‐TKIs, the clinical and imaging findings of this case were consistent with TAPOs. For TAPOs occurring because of MET‐TKI, the drug can be continued under careful observation even if GGOs appear.