Chronic lymphocytic leukemia(CLL) is a prevalent form of leukemia and it most frequently occurs in older adults. Leptomeningeal Involvement in chronic lymphocytic leukemia is very rare.

The patient is a 79 year old man with a past history of controlled CLL which admitted 5 days ago with fever, shaking chills, vomiting, coma and neck stiffness. Evaluations for infectious meningitis were negative and he did not respond to antibiotics and antiviral medications. Intrathecal methotrexate caused improvement of clinical and cerebrospinal fluid abnormalities.

Clinical manifestations of leukemic meningitis can mimic acute bacterial meningitis.