Leukemic Meningitis as the Presenting Manifestation of Chronic Lymphocytic Leukemia (CLL) in a Young Man.

Meningeal infiltration is extremely rare in CLL. Moreover, part of the cases found in the literature occurred in fact in patients with prolymphocytic leukemia. In the few CLL cases, this complication was reported at late stages of the disease, in elderly patients. A previously healthy 30-year-old man was referred to the emergency department for evaluation of blurred vision and headache that developed 2 weeks earlier. Bilateral papilledema was observed, with no other neurological abnormality. CT and MRI of the head and orbits disclosed thickening of both optic nerves. Hemoglobin and platelet count were within normal limits. The WBC count was 41800/μl with 83% small lymphocytes, which were SmIg+ λ(weak) CD19+, CD5+, CD23+, CD20+, CD79b+, CD11c+, bcl2+, CD38+, ZAP70+ and CD10 negative. Moderately enlarged cervical lymph nodes were present. A diagnosis of Binet stage A, Rai stage I B-CLL was made. Bone marrow aspiration and biopsy showed 95% lymphocytes, with a diffuse pattern of infiltration. No metaphases were obtained for karyotyping. FISH disclosed a rearranged IgH, and was negative for trisomy 12 and for deletions of 11q, 13q and 17q. Abdominal CT showed retroperitoneal lymphadenopathy. Serology for HIV and EBV was negative. The cerebrospinal fluid (CSF) revealed >1000 lymphocytes/μl which were immunophenotypically identical to the peripheral blood cells. Systemic corticosteroids and intrathecal chemotherapy (methotrexate and dexamethasone) followed by cranial irradiation led to resolution of headache, but blurred vision persisted. Clearance of leukemic cells from the CSF was slow, a normal CSF being achieved only after 6 alternate day intrathecal injections. Systemic chemotherapy and stem cell transplantation are planned. To our knowledge this is the first reported case of CLL presenting as meningeal infiltration. Two possible reasons for the apparent rarity of CLL meningitis can be put forward: meningeal invasion would frequently be clinically silent, a hypothesis that is strengthened by autopsy findings; and it would usually occur in very advanced stages of CLL (with misinterpretation of neurological symptoms in erderly patients) making underdiagnosis easy.