Lambert-eaton myasthenic syndrome in a patient with small-cell lung cancer.

Lambert-Eaton myasthenic syndrome (LEMS), an autoimmune neuromuscular disorder, often has underlying small-cell lung cancer (SCLC). Thorough search for SCLC in patients with LEMS can result in early detection of limited-stage SCLC, one quarter of which can be successfully treated with chemotherapy and radiation therapy. To elucidate the pathogenesis, diagnosis, treatment, and prognosis of patients with SCLC and LEMS, we present a 51-year-old man who was diagnosed with LEMS and limited-stage SCLC after an 18-month history of weakness in the lower extremities. The patient exhibited a complete response in lung tumors and a resolution in LEMS symptoms after chemotherapy and radiation therapy.