Malignant meningitis secondary to lung adenocarcinoma: an unusual relapse.

We describe a 64-year-old man with locally advanced lung adenocarcinoma who had meningeal relapse soon after the completion of intensive chemo-radiotherapy. Diagnosis of the malignant meningitis was established by cytological examination of the cerebrospinal fluid, which showed malignant cells consistent with adenocarcinoma from the primary site. Although very rare, it is possible that successful chemo-radiotherapy for locally advanced lung cancer could not prevent malignant meningitis as observed in our patient. Physicians should consider performance of brain MRI or contrast CT of the brain and a lumbar puncture to exclude the diagnosis of malignant meningitis, an uncommon but devastating complication of malignancy.