title: Orbital and central nervous system extension of nasal natural killer/T-cell lymphoma.
abstract: BACKGROUND
  To describe a case series of nasal natural killer (NK)/T-cell lymphoma (NKTL) with orbital and central nervous system extension.
  
  
  METHODS
  This is a retrospective study. The medical records of 9 patients with a diagnosis of NKTL were reviewed. All patients had a positive biopsy for CD3, CD56, T-cell-restricted intracellular antigen-1, and granzyme expression and CT imaging of nose, sinuses, orbits, and brain. Five patients were also examined with MRI.
  
  
  RESULTS
  Orbital extension occurred in 6 patients. All had extraocular muscle enlargement and 5 showed signs of perineural spread.
  
  
  CONCLUSIONS
  NKTL is a polymorphous disease. Extraocular muscle involvement and perineural spread are overlooked features that explain dissemination of the tumor to both the orbit and the central nervous system.
authors.affiliation: *School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil; †King Khaled Eye Specialist Hospital, Johns Hopkins University; ‡Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, §Department of Pathology, and ‖Department of Radiology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Antonio A V
authors.initials: AA
authors.lastname: Cruz
authors.forename: Fabiana C P
authors.initials: FC
authors.lastname: Valera
authors.forename: Lucas
authors.initials: L
authors.lastname: Carenzi
authors.forename: Fernando
authors.initials: F
authors.lastname: Chahud
authors.forename: Gyl E
authors.initials: GE
authors.lastname: Barros
authors.forename: Jorge
authors.initials: J
authors.lastname: Elias
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D017252:CD3 Complex / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism; D016543:Central Nervous System Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D002648:Child; D005260:Female; D053804:Granzymes / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000378:metabolism / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009918:Orbital Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D017252:CD3 Complex; D019002:CD56 Antigen; C522918:NCAM1 protein, human; D016601:RNA-Binding Proteins; C076751:TIAL1 protein, human; D053804:Granzymes