Invasion of small cell lung cancer into the limbic system from leptomeningeal metastases

The diagnosis of leptomeningeal metastases is sometimes difficult when the cytology of cerebrospinal fluid is negative. We report a rare case of leptomeningeal metastases that required differentiation from paraneoplastic limbic encephalitis. A 67-year-old man with extensive-stage small cell lung cancer was admitted for a sudden decrease in the level of consciousness. He suffered memory disturbances that began the day before admission....