<scp>MET</scp> Exon 14 Skipping Mutation‐Positive Lung Cancer With Multiple Cystic Airspaces: A Case Report

ABSTRACT Lung cancer with cystic airspaces (LCCA) is an uncommon radiological presentation that is frequently underrecognised and may be mistaken for benign or infectious pulmonary conditions. We report a case of lung adenocarcinoma presenting with multiple thin‐walled cystic lesions harbouring a MET exon 14 skipping mutation. A 65‐year‐old woman presented with chronic cough and expectoration. Chest imaging revealed multiple cavitary and cystic pulmonary lesions accompanied by mediastinal lymphadenopathy and distant metastases. Endobronchial ultrasound‐guided transbronchial needle aspiration confirmed adenocarcinoma with a MET exon 14 skipping mutation. The patient was diagnosed with Stage IV disease and initiated on tepotinib therapy, resulting in marked regression of the pulmonary lesions. This case underscores the importance of considering malignancy in the differential diagnosis of thin‐walled cystic lung lesions and suggests that MET exon 14‐positive LCCA may represent a distinct molecular subgroup with favourable responsiveness to MET‐targeted therapy.