[A case of paraneoplastic syndrome improved following chemoradiotherapy for lung cancer].

Paraneoplastic neurosyndrome (PNS) is a group of neurological disorders caused by or associated with neoplasms that are not direct effects of the primary tumor or of a metastasis to the involved organs. Chemotherapy, radiotherapy, immunosuppressive therapy, and plasmapheresis have been performed to treat PNS, but improvement of the neurological disorder is rather rare. A 64-year-old man was referred to our hospital with dysesthesia of the extremities and ataxic gait. Small cell lung cancer was diagnosed in another hospital and chemotherapy (CDDP 80 mg/m2 + VP-16 100 mg/m2) was performed. A partial response was obtained with this treatment, but the neurological dysfunction was exacerbated. Three months later, the patient was admitted to our hospital. On treatment with CDDP 80 mg/m2 (day 1) and CPT-11 80 mg/m2 (days 1, 8 and 15) and subsequent radiation therapy (60 Gy), his neurological disorder improved. We consider that neurological symptoms are important signs of malignancy in PNS and that a full course of treatment could improve the neurological disorders.