A 66-year-old man presented with fever and headache that had lasted for 3 months. The headache had a continuous pressing quality and bilateral involvement. He had a history of undifferentiated arthritis, for which he had undergone a treatment with chroloquine, leading to disease remission 2 years prior. He also had long term hypertension and diabetes. Current medications included enalapril, metformin, and chroloquine. He was febrile with body temperature of 38.5°C. Neither nuchal rigidity nor lymphadenopathy was detected. The findings of other general and neurological examinations were unremarkable. Magnetic resonance imaging (MRI) of the brain revealed thickening of the falx cerebri with diffuse pachymeningeal enhancement (Figure 1). A lumbar puncture revealed an opening pressure of 200 mm H₂O. Cerebrospinal fluid (CSF) analysis showed a white blood cell count of 785 cells/mm³ with 62% lymphocytes and 38% neutrophils, a protein level of 72 mg/dL, and a glucose level of 80 mg/dL (concurrent a blood glucose level of 182 mg/dL). The results of Gram and Ziehl-Neelsen staining, India ink preparation, cryptococcal antigen, tuberculosis polymerase chain reaction, and culture for bacteria were negative. The CSF culture, which was subsequently reported, was also negative for Mycobacterium tuberculosis . The adenosine deaminase (ADA) level in CSF, which was determined by an automated method, was 11.1 U/L. Blood serological study for Venereal Disease Research Laboratory was nonreactive. The result of a chest X-ray was within the normal limits. The patient denied performing the meningeal biopsy. Diffuse hypertrophic pachymeningeal tuberculosis was suspected due to the patient having symptoms of prolonged fever and headache, lymphocytic CSF pleocytosis with elevated protein level and low CSF-to-serum glucose ratio, and a high level of CSF-ADA. The patient was treated with combined antituberculous drugs [isoniazid (I), rifampin (R), pyrazinamide (Z), ethambutol (E)], for 2 months, followed by IR (isoniazid, rifampin) for 4 months [1]. The fever and headache gradually disappeared. A follow-up MRI of the brain revealed a marked decreased in the thickening of the falx cerebri and pachymeningeal enhancement (Figure 2). The results of repeat CSF analysis and the level of CSF-ADA were within normal ranges.