title: T- and NK-Cell Lymphomas and Systemic Lymphoproliferative Disorders and the Immunodeficiency Setting: 2015 SH/EAHP Workshop Report-Part 4.
abstract: OBJECTIVE
  The 2015 Workshop of the Society for Hematopathology/European Association for Haematopathology aimed to review immunodeficiency-related T- and natural killer (NK)-cell lymphoproliferations.
  
  
  METHODS
  The Workshop Panel reviewed 88 T- or NK-cell lymphoproliferations and rendered consensus diagnoses.
  
  
  RESULTS
  Hyperplasias of T-cell subsets may be clonal; retained architecture and the clinical setting support a benign diagnosis. Specific associations include hepatosplenic T-cell lymphoma with iatrogenic immunosuppression and breast implants with an indolent variant of anaplastic large cell lymphoma. Epstein-Barr virus (EBV)-positive T-cell lymphomas rarely occur in the acquired immunodeficiency setting. Systemic T- and NK-cell lymphoma of childhood overlaps with chronic active EBV and reversible hemophagocytic lymphohistiocytosis-related T-cell lymphoproliferations.
  
  
  CONCLUSIONS
  Immunodeficiencies predispose to T-cell hyperplasias, which must not be overdiagnosed as lymphoma. Many T-cell lymphomas in the immunodeficiency setting are likely coincidental, with specific exceptions. Systemic T- or NK-cell lymphomas are part of a spectrum of EBV+ T or NK lymphoproliferations and can present in the acquired immunodeficiency setting.
authors.affiliation: From the Stanford University School of Medicine, Stanford, CA.
authors.forename: Dita
authors.initials: D
authors.lastname: Gratzinger
authors.affiliation: VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Daphne
authors.initials: D
authors.lastname: de Jong
authors.affiliation: National Institutes of Health, Bethesda, MD.
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Jaffe
authors.affiliation: Weill Medical College of Cornell University, New York, NY.
authors.forename: Amy
authors.initials: A
authors.lastname: Chadburn
authors.affiliation: Queen Elizabeth Hospital, Kowloon, Hong Kong.
authors.forename: John K C
authors.initials: JK
authors.lastname: Chan
authors.affiliation: University of Leeds, Leeds, United Kingdom.
authors.forename: John R
authors.initials: JR
authors.lastname: Goodlad
authors.affiliation: University of California Los Angeles Medical Center, Los Angeles.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Said
authors.affiliation: From the Stanford University School of Medicine, Stanford, CA.
authors.forename: Yasodha
authors.initials: Y
authors.lastname: Natkunam
mesh_terms: D004493:Education; D020031:Epstein-Barr Virus Infections / Q000150:complications; D005260:Female; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000150:complications* / Q000276:immunology; D054391:Lymphoma, Extranodal NK-T-Cell / Q000175:diagnosis* / Q000276:immunology; D016399:Lymphoma, T-Cell / Q000175:diagnosis* / Q000276:immunology; D008232:Lymphoproliferative Disorders / Q000175:diagnosis* / Q000276:immunology; D008297:Male
keywords: Iatrogenic immunodeficiency; NK-cell lymphoma; Posttransplant lymphoproliferative disorder; Systemic T- or NK-cell lymphoma of childhood; T-cell lymphoma