Leptomeningeal involvement in chronic lymphocytic leukemia.

PURPOSE: This review and case report address the rare complication of leptomeningeal involvement in patients with chronic lymphocytic leukemia. OVERVIEW: Chronic lymphocytic leukemia is the most common form of leukemia, with more than 200,000 cases reported in the past 20 years. An uncommon complication of the disorder is central nervous system invasion. To date, only 21 cases have been reported, and their presenting symptoms have been heterogeneous and often nonspecific, including headache, cranial nerve abnormalities, confusion, ataxia, nausea, vomiting, and fever. The diagnosis is confirmed by the presence of a clonal population of lymphocytes in the cerebrospinal fluid. Treatment is either intrathecal or intraventricular chemotherapy with adjuvant radiation therapy or radiation alone. Prognosis is improved by prompt and aggressive therapy. In this case report, a 61-year-old man developed severe ataxia, vertigo, and occipital headaches 4 weeks after diagnosis with otherwise asymptomatic chronic lymphocytic leukemia. After treatment with both radiation to the head and neck and intrathecal methotrexate the patient achieved complete symptom resolution. Thus far, no additional systemic cytotoxic chemotherapy has been necessary. CLINICAL IMPLICATIONS: Because central nervous system invasion is uncommon in chronic lymphocytic leukemia, it may go undiagnosed and under-reported. Providers of patients with this disease need to be aware of possible central nervous system invasion when patients present with cranial nerve signs or symptoms and/or nonspecific neurologic manifestations. Early identification and prompt central nervous system-directed chemotherapy can affect morbidity and quality of life positively.