Paraneoplastic neurological syndrome in a patient with squamous cell lung cancer

A 78-year-old man presented with urinary retention and difficulty walking. Both legs showed muscle weakness, and he was experiencing lower body hypoesthesia. T2-weighted magnetic resonance imaging revealed lesions with high signal intensity and enhancement in the spinal cord and cerebrum. A cerebrospinal fluid specimen showed inflammatory changes, but negative cytology findings. Chest computed tomography revealed a tumor measuring 40 mm in diameter, and a lung biopsy revealed the presence of squamous cell carcinoma. We diagnosed the patient with paraneoplastic neurological syndrome related to lung cancer. The patient was treated with steroid pulse therapy and chemotherapy, which relieved the symptoms and enabled the patient to achieve an independent gait.