Introduction Chronic lymphocytic leukemia (CLL) is the most common leukemia diagnosed in the United States. 1 However, the occurrence of leptomeningeal involvement in CLL is very rare, as only a few cases are reported in the literature. 1-7 Meningeal disease begins insidiously, with subtle symptoms followed by rapid progression. Because suspicion of leptomen- ingeal involvement in CLL is low, a definitive diagnosis is usually delayed. In this report, we describe a patient with CLL who developed visual disturbances after receiving multiple chemotherapeutic regimens. Leptomeningeal involvement was diagnosed by cerebrospinal fluid (CSF) flow cytometry and magnetic resonance imaging (MRI). Case Report A 59-year-old white man was diagnosed with CLL in 1998 with stages A and 0 of the Binet and Rai classifications, respectively. It was decided to proceed with a watch-and-wait approach. Three years later, bulky lymphadenopathy 1 Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Johns Hopkins University School of Medicine, Baltimore, MD 2 Escuela de Medicina “Ignacio A. Santos,” Instituto Tecnológico y de Estudios Superiores de Monterrey, Nuevo Leon, Mexico 3 Department of Pathology, Johns Hopkins Hospital, Johns Hopkins University School of Medicine, Baltimore, MD 4 Auerbach Hematology and Oncology, Baltimore, MD 5 Georgetown University School of Medicine, Washington, DC Submitted: Jan 31, 2007; Revised: Feb 21, 2007; Accepted: Mar 20, 2007 Address for correspondence: Javier Bolaños-Meade, MD, Division of Hematologic Malignancies, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Bunting Blaustein Cancer Research Bldg, 1650 Orleans St, Room 2M-87, Baltimore, MD 21231-1000 Fax: 410-955-1969; e-mail: fbolano2@jhmi.edu Meningeal Involvement in a Patient with Chronic Lymphocytic Leukemia and Richter’s Transformation Chronic lymphocytic leukemia (CLL) rarely involves the meninges. There are few cases published in the lit- erature. In this report, we describe a 59-year-old man with an 8-year history of CLL who presented with bone marrow involvement and cytopenias; received therapy with rituximab, fludarabine, pentostatin, and cyclophos- phamide; and later went on to receive alemtuzumab. He developed leptomeningeal infiltration presenting as diplopia. The cerebrospinal fluid revealed a white blood cell count of 51/mm 3 ; all of them were mononuclear, and the diagnosis was confirmed to be CLL by flow cytometry. A gadolinium magnetic resonance imaging scan of the head showed abnormal enhancement extending from the choroids in the left ventricle into the right ventricle, as well as changes in intensity in the splenium of the corpus callosum and left cerebellar peduncle. Whole-brain irradiation (2500 cGy) and 5 cycles of intrathecal cytarabine were administered. After this, a diffuse large B-cell lymphoma of the right testicle was discovered. An orchiectomy was performed, followed by radiation to the testicular bed. Persistent leptomeningeal involvement was treated with intrathecal methotrexate, resulting in a remission. A matched, unrelated donor bone marrow transplantation was performed. Clinical Leukemia, Vol. 1, No. 3, 192-194, 2007 Key words: Cerebrospinal fluid, Intrathecal chemotherapy, Meningeal carcinomatosis María de Lourdes Quintanilla-Dieck, 1,2 Myriam Loyo, 1,2 Zarir Karanjawala, 3 Matthew Georgy, 3 Douglas P. Clark, 3 Michael Auerbach, 4,5 Javier Bolaños-Meade 1 Clinical Leukemia • March 2007 192 Electronic forwarding or copying is a violation of US and International Copyright Laws. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by CIG Media Group, LP, ISSN #1931-6925, provided the appropriate fee is paid directly to Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923 USA 978-750-8400. Case Report Abstract