Consequently, the emergence of actionable driver mutations following systemic therapy is an exceptionally rare but clinically significant phenomenon in this entity.<h4>Case presentation</h4>We present the case of a 52-year-old male diagnosed with stage T4N3M1a (IVA) SMARCA4-dNSCLC in April 2023, initially presenting with superior vena cava syndrome (SVCS). The gene discussed is SMARCA4; the disease is Superior Vena Cava Syndrome.