title: Primary natural killer/T-cell lymphoma presenting as leptomeningeal disease.
abstract: BACKGROUND
  Primary central nervous system natural killer/T-cell lymphoma (primary-CNS-NK/TCL) is a rare non-Hodgkin's lymphoma. To our knowledge, only five patients have been described previously, all of whom were male, with brain parenchymal involvement and previous Epstein-Barr virus infection, it has never been reported to present as leptomeningeal disease as our case. Our objective is to report a rare case of primary-CNS-NK/TCL presenting as leptomeningeal disease and to share our diagnostic/therapeutic approach to this rare disease.
  
  
  METHODS
  We report a rare case of primary-CNS-NK/TCL presenting as leptomeningeal disease. The patient was diagnosed and treated at The University of Texas MD Anderson Cancer Center.
  
  
  RESULTS
  The patient presented with multiple cranial neuropathies and gait ataxia. Brain and spinal cord magnetic resonance imaging demonstrated leptomeningeal enhancement of the cerebellar folia/vermis, spinal cord dura, and both temporal lobes as well as adjacent brain parenchymal disease. Cerebrospinal fluid (CSF) revealed atypical lymphoma cells of NK/T-cell lineage by flow cytometric immunophenotyping. Molecular analysis using real-time quantitative polymerase chain reaction did not detect Epstein-Barr virus DNA in the lymphoma cells. Bone marrow biopsy revealed no morphologic, flow cytometric, or immunohistochemical evidence of B-, T- or NK-cell lymphoma. Slit-lamp examination demonstrated no evidence of intraocular lymphoma. Whole-body PET scan showed no evidence of malignancy other than CNS disease. The patient was given systemic chemotherapy with high-dose methotrexate, vincristine, and procarbazine, along with intrathecal therapy with free cytarabine. The patient showed clinicoradiographic improvement and CSF cytology became negative.
  
  
  CONCLUSIONS
  This case highlights an atypical presentation of primary-CNS-NK/TCL with a potentially successful treatment regimen.
authors.affiliation: Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, 1400 Holcombe Boulevard, Room FC7.3000, Unit 431, Houston, TX 77030, United States; Department of Neurology, The University of Texas Medical Branch, 301 University Boulevard, Room JSA 9.128, Galveston, TX 77555, United States. Electronic address: biliao@utmb.edu.
authors.forename: Bing
authors.initials: B
authors.lastname: Liao
authors.affiliation: Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, 1400 Holcombe Boulevard, Room FC7.3000, Unit 431, Houston, TX 77030, United States.
authors.forename: Carlos
authors.initials: C
authors.lastname: Kamiya-Matsuoka
authors.affiliation: Department of Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Office G3.3775, Houston, TX 77030, United States.
authors.forename: Yun
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, 1400 Holcombe Boulevard, Room FC7.3000, Unit 431, Houston, TX 77030, United States.
authors.forename: Merry
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Neurology, Baylor College of Medicine, Mailing Address: 6501 Fannin Street, NB320, Houston, TX 77030, United States.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Wolf
authors.affiliation: Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, R6.1617, Houston, TX 77030, United States.
authors.forename: Nathan H
authors.initials: NH
authors.lastname: Fowler
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology; D016543:Central Nervous System Neoplasms / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D016399:Lymphoma, T-Cell / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008577:Meningeal Neoplasms / Q000503:physiopathology*
keywords: CNS lymphoma; Epstein–Barr virus; Leptomeningeal disease; Natural killer/T-cell lymphoma