Transformation of invasive lung adenocarcinoma with ALK rearrangement into pulmonary sarcomatoid carcinoma.

This case first reported a patient with invasive lung adenocarcinoma harboring ALK rearrangement who underwent histological transformation into sarcomatoid carcinoma after ALK TKI resistance, and MET amplification might represent the cause. After transformation, the patient benefited from targeted therapy combined with chemotherapy, which represents a promising option for patients with sarcomatoid carcinoma transformation.