Pulmonary sarcomatoid carcinoma with METex14 mutation and high PD-L1: A case report.
Junzhang Qin, Zhen Xiong
✦ AI-curated · Sources linked
Case in brief
A previously healthy 54-year-old man presented with persistent cough and diminished breath sounds over the right upper lung. Bronchoscopic biopsy suggested inflammation, while CT-guided biopsy showed atypical giant cells but was inconclusive. Surgical resection established pleomorphic (sarcomatoid) carcinoma, staged as IIIB (T4N2M0). Testing found a MET exon 14 skipping mutation and PD-L1 tumor proportion score ≥ 50%. After an initial cycle of toripalimab with docetaxel and lobaplatin, treatment was changed to a MET inhibitor with the same chemotherapy. He had a partial response maintained for over 6 months; his cough resolved and general condition remained good.
What made this case unusual
The case combined METex14 mutation with high PD-L1 expression in pulmonary sarcomatoid carcinoma, while initial bronchoscopic and CT-guided biopsies did not establish the diagnosis.
Diagnostic / clinical pearl
Pulmonary sarcomatoid carcinoma may be difficult to diagnose on limited biopsy; when findings are inconclusive, multidisciplinary assessment and definitive pathology can clarify the diagnosis. Molecular and PD-L1 testing can identify treatment-relevant features.
Why it matters
The optimal first-line approach for PSC with both METex14 mutation and high PD-L1 expression remains undefined; this case illustrates the uncertainty around choosing targeted therapy versus immunotherapy.