Chronic lymphocytic leukemic meningitis as a cause of the syndrome of inappropriate secretion of antidiuretic hormone.

A patient with B-cell chronic lymphocytic leukemia (CLL) is described who presented with fever, headache, and hyponatremia. Subsequent evaluation established the diagnoses of CLL meningitis and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Both findings resolved following therapy with intrathecal methotrexate. A brief citation of the literature of CLL meningitis is presented.