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Abstract

Introduction: Leukemic meningitis (LM) is a relatively rare central nervous system (CNS) complication in the era of induction protocols with CNS prophylaxis. We describe a patient with LM as the initial presentation of Acute B-lymphoblastic leukemia (B-ALL). Case Presentation: A 59-year-old female with no significant past medical history presented with 2 weeks of progressive weakness and altered mental status. On examination, she was tachypneic, tachycardic and hypotensive with a systolic blood pressure of 80 mm Hg. An arterial blood gas revealed a pH of 6.8 with a bicarbonate level of 8. She was intubated and started on vasopressors after initial fluid resuscitation. Laboratory investigation showed hemoglobin of 2 mg/dl, thrombocytopenia, leucocytosis of 96000 cell/dl including 43% atypical cells and severe metabolic acidosis with a lactate of 23.6. Chest radiograph showed bilateral patchy consolidation. A lumbar puncture showed 23 WBCs and 80% blast cells. Subsequently, flow cytometry of the peripheral blood showed 80-85% blast cells positive for Tdt, CD-19 and CD-20. Computed tomography (CT) of the chest and abdomen was negative for significant lymphadenopathy. Patient was diagnosed with acute B-cell lymphoblastic leukemia with leukemic meningitis and septic shock secondary to bilateral pneumonia. She was treated with intrathecal methotrexate and prednisone. Patient responded well to induction chemotherapy with Vincristine and was discharged after 2 months of hospitalization. Currently she is undergoing her second phase of consolidation chemotherapy. Discussion: Meningitis in leukemia may result from direct infiltration such as leukemic meningitis, subarachnoid hemorrhage, chemical (following intrathecal chemotherapy) or infectious [1]. Leukemic meningitis may be seen at diagnosis (3-5% patients with ALL) or at relapse, even with prior CNS prophylaxis. Malignant cells are thought to enter the CNS by hematogenous spread, direct extension from adjacent bone metastases, by centripetal growth along neurovascular bundles or spread from bone marrow via the intervertebral venous plexus [2].The diagnosis of CNS leukemia is usually easily confirmed by the identification of leukemic blasts on cytocentrifuge preparations of cerebrospinal fluid (CSF) after lumbar puncture. Relapse of LM carries a poor prognosis with a median survival of 6 months. Various treatment options include intrathecal chemotherapy (IT), systemic chemotherapy, and cranial radiation in patients. Conclusion: Acute leukemia can present with diverse CNS manifestations. All patients with a suspected CNS dysfunction should be promptly evaluated with a lumbar puncture to diagnose and hence avoid the dreaded complications of LM.