Neoplastic meningitis due to colorectal cancer.

Herein, we describe a rare case of neoplastic meningitis in a 54-year-old male with a history of colorectal cancer. He first noticed a loss of sensation in his left thigh along with back pain. Magnetic resonance imaging showed a tumor lesion in the cauda equina. The tumor was surgically resected and pathologically diagnosed as a metastatic tumor of the descending colon cancer for which he had undergone resection a year earlier. The patient was treated with chemotherapy using capecitabine, oxaliplatin, and cetuximab. During chemotherapy, his tumor markers decreased and magnetic resonance imaging showed tumor shrinkage, but he became aware of neurological symptoms such as hearing loss, tinnitus, and headache. The patient's condition suddenly worsened during the 5th course of chemotherapy and he died 5 months after the diagnosis. Neoplastic meningitis occurs in 4-15% of patients with solid tumors, but it is rarely seen in colorectal cancer. It should be considered when a patient with a history of cancer has back pain or neurological symptoms. The progression of neoplastic meningitis is fast and it has a poor prognosis. Diagnosis in the early stages is important to prevent progression of neurological symptoms and to provide the most effective treatment.