[A case of small-cell lung cancer associated with paraneoplastic limbic encephalitis during chemotherapy]

A 75-year-old woman received a diagnosis of small-cell lung cancer (T1N2M0, stage IIIA, limited disease) in January 2009. She received 4 cycles of chemotherapy with etoposide and carboplatin and concurrent radiotherapy (50 Gy/25 Fr) which yielded a complete response. However, recurrence of her small-cell lung cancer occurred in a mediastinal lymph node and the ribs in November 2009. During the 2nd cycle of second-line chemotherapy with nogitecan, she was readmitted to our hospital complaining of amnesia, periods of unconsciousness and convulsions. Her laboratory data on admission revealed normal serum electrolyte and cerebrospinal fluid levels, and electroencephalogram findings. Her neurological symptoms, which mimicked limbic encephalitis improved after steroid pulse therapy plus third-line chemotherapy with amrubicin. The final diagnosis was paraneoplastic limbic encephalitis by positive serum voltage-gated calcium channel antibodies. We hereby report a rare case of small-cell lung cancer associated with paraneoplastic limbic encephalitis during chemotherapy.