Introduction: Lung cancer is the second most common cancer; however, synchronous lung cancer is rare and challenging to treat.

Case presentation: We report the case of an 80-year-old female patient who presented with two lung lesions with primary tumor characteristics, which revealed squamous cell carcinoma and synchronous adenocarcinoma after histological sampling. Next-generation sequencing (NGS) analysis revealed a MET Exon 14 skipping mutation in squamous cell carcinoma and an epidermal growth factor receptor mutation in adenocarcinoma. Capmatinib and stereotactic radiotherapy were initiated for the adenocarcinoma with a good clinical response. Capmatinib treatment had to be discontinued because of stage 3 edema of the lower limbs, after which a left lobectomy was performed. Currently, the patient is considered to be in remission.

Conclusion: This case highlights the need for histological analysis of every lung lesion with primary tumor characteristics, as well as for NGS analysis in search of specific mutations enabling the introduction of targeted therapies. mesenchymal-epithelial transition.