title: First case of primary intraocular natural killer t-cell lymphoma.
abstract: BACKGROUND
  Natural killer cell tumors can be broadly divided by origin into mature-cell and progenitor-cell types. The invasion of nasal-origin natural killer cells into the ophthalmologic field is sometimes observed in patients, but primary ocular natural killer cell tumors are a rare occurrence.
  
  
  METHODS
  A 66 year-old woman without any systemic disease presented with blurred vision due to a severe vitreous opacity in the right eye. Flow cytometric analysis of the vitreous fluid suggested a natural killer cell tumor. Moreover, cytologic examination of vitreal and retinal specimens revealed the infiltration of a natural killer cell tumor, while PCR and immunocytochemistry revealed Epstein-Barr virus infection. The results of a gene rearrangement analysis were positive for IGH, while TCR beta chains were all negative. We examined the patient with whole-body magnetic resonance imaging and positron emission tomography, and performed a bone marrow examination. These examinations returned no abnormal results.
  
  
  CONCLUSIONS
  Thorough analysis of vitreal samples is essential when performing vitrectomies for vitreous opacities of unknown cause. Flow cytometric, cytologic, and PCR analysis of vitreal and retinal samples may reveal the presence and cause of severe illness.
authors.affiliation: Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, Japan. maruyama-k@oph.med.tohoku.ac.jp.
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Maruyama
authors.affiliation: Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, Japan. kunikata@oph.med.tohoku.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kunikata
authors.affiliation: RIKEN Center for Development Biology, Kobe, Japan. sunaoph@cdb.riken.jp.
authors.forename: Sunao
authors.initials: S
authors.lastname: Sugita
authors.affiliation: Department of Ophthalmology, Tokyo Dental and Medical University, Tokyo, Japan. m.manabu.oph@tmd.ac.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Mochizuki
authors.affiliation: Department of Hematopathology, Tohoku University Graduate School of Medicine, Sendai, Japan. ryo@med.tohoku.ac.jp.
authors.forename: Ryo
authors.initials: R
authors.lastname: Ichinohasama
authors.affiliation: Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, Japan. ntoru@oph.med.tohoku.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Nakazawa
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism; D018801:CD2 Antigens / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism; D003131:Combined Modality Therapy; D004279:DNA, Viral / Q000235:genetics; D020031:Epstein-Barr Virus Infections / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy / Q000821:virology; D015828:Eye Infections, Viral / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy / Q000821:virology; D005260:Female; D005434:Flow Cytometry; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D016399:Lymphoma, T-Cell / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy / Q000821:virology; D008279:Magnetic Resonance Imaging; D055611:Natural Killer T-Cells / Q000276:immunology*; D016133:Polymerase Chain Reaction; D049268:Positron-Emission Tomography; D019572:Retinal Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000628:therapy / Q000821:virology; D041623:Tomography, Optical Coherence; D014822:Vitreous Body / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D018801:CD2 Antigens; D019002:CD56 Antigen; D004279:DNA, Viral; C522918:NCAM1 protein, human