Lambert-Eaton syndrome associated with small cell lung cancer

Introduction: Lambert-Eaton syndrome is a paraneoplastic presynaptic neuromuscular disorder frequently associated with small cell lung cancer (SCLC). Case presentation: A 61-year-old male presenting with progressive muscle weakness and oropharyngeal xerosis was diagnosed with Lambert-Eaton syndrome via electroneurogram and voltage-gated calcium channel antibodies. PET-CT detected a mass compatible with limited-stage SCLC, confirmed by EBUS. After four cycles of concurrent chemoradiotherapy (cisplatin-etoposide), he achieved complete radiological response and neurological remission. He completed 24 months of consolidation Durvalumab after enrollment in the ADRIATIC trial, currently maintaining complete response. Discussion: This case highlights the direct relationship between tumor control and symptomatic remission of the syndrome, as well as the impact of consolidation immunotherapy with Durvalumab following chemoradiotherapy. Conclusions: Consolidation with Durvalumab (ADRIATIC) provided a clear clinical benefit, maintaining a sustained complete response over four years with a manageable toxicity profile and excellent quality of life.