Paraneoplastic and metastatic neurologic complications of Merkel cell carcinoma.

Merkel cell carcinoma is a rare primary cutaneous neuroendocrine tumor that is locally aggressive and frequently accompanied by distant metastases. Neurologic complications of Merkel cell carcinoma are rare. We describe a 69-year-old man who presented with Lambert-Eaton myasthenic syndrome and was found to have Merkel cell carcinoma. The paraneoplastic syndrome improved with initial treatment of the malignancy. He subsequently developed a solitary brain metastasis and died of leptomeningeal carcinomatosis.