A case of Lambert–Eaton myasthenic syndrome associated with pancreatic neuroendocrine tumor

Lambert–Eaton myasthenic syndrome is an immune‐mediated disorder of the presynaptic neuromuscular junction that occurs in paraneoplastic and nontumor forms. Lambert–Eaton myasthenic syndrome is most commonly associated with small‐cell lung cancer, but has also been reported with other neuroendocrine tumors including large‐cell neuroendocrine tumor of the lung, atypical carcinoid, thymic neuroendocrine tumor, and Merkel cell carcinoma. We here report a case of electro‐diagnostically confirmed Lambert–Eaton syndrome in a patient who was found to have pancreatic neuroendocrine tumor with positive P/Q‐type calcium channel antibodies.