title: Expression of helper T cell master regulators in inflammatory dermatoses and primary cutaneous T-cell lymphomas: diagnostic implications.
abstract: BACKGROUND
  Mycosis fungoides (MF) is a neoplasm of skin-homing CD4(+) helper T (TH) lymphocytes with dysregulation of TH1 and TH2 immunity. Diagnosis of MF is challenging, as there is significant morphologic overlap with other dermatologic entities.
  
  
  OBJECTIVE
  We investigated diagnostic utility of TH1- and TH2-specific markers, T-bet, and GATA-3, respectively, in MF and its reactive and neoplastic mimics.
  
  
  METHODS
  Immunohistochemical staining for CD3/T-bet and CD3/GATA-3 was performed on inflammatory dermatoses (n = 56), MF (n = 37), Sezary syndrome (SS; n = 8), and cutaneous anaplastic large cell lymphoma (C-ALCL; n = 14).
  
  
  RESULTS
  Inflammatory dermatoses showed epidermal T cells predominantly expressing GATA-3, except psoriasis, which exhibited a mixed GATA-3/T-bet staining. In contrast, neoplastic T cells in patch stage MF showed markedly increased T-bet positivity with minimal GATA-3 expression. Plaque stage MF had a mixed T-bet/GATA-3 phenotype, whereas tumor stage MF and SS exhibited diffuse GATA-3 expression. C-ALCL lacked significant staining for both markers.
  
  
  CONCLUSIONS
  Sample size was relatively small.
  
  
  CONCLUSIONS
  A predominance of T-bet(+) T cells in the epidermis support patch stage MF over dermatitis. A predominance of GATA-3(+) T cells in the dermis support CD30(+) MF with large cell transformation over C-ALCL. These stains do not allow distinction between dermatitis and cutaneous infiltrates of SS.
authors.affiliation: Washington University Dermatopathology Center, Washington University School of Medicine, St. Louis, Missouri; Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Andy C
authors.initials: AC
authors.lastname: Hsi
authors.affiliation: Division of Dermatology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Sena J
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Washington University Dermatopathology Center, Washington University School of Medicine, St. Louis, Missouri; Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri; Division of Dermatology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Ilana S
authors.initials: IS
authors.lastname: Rosman
authors.affiliation: Division of Medical Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Carson
authors.affiliation: Washington University Dermatopathology Center, Washington University School of Medicine, St. Louis, Missouri; Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Amanda
authors.initials: A
authors.lastname: Kelley
authors.affiliation: Washington University Dermatopathology Center, Washington University School of Medicine, St. Louis, Missouri; Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Valerie
authors.initials: V
authors.lastname: Viele
authors.affiliation: Department of Biology, Washington University, St. Louis, Missouri.
authors.forename: Xiaofan
authors.initials: X
authors.lastname: Pang
authors.affiliation: Division of Dermatology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Amy
authors.initials: A
authors.lastname: Musiek
authors.affiliation: Washington University Dermatopathology Center, Washington University School of Medicine, St. Louis, Missouri; Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri; Division of Dermatology, Washington University School of Medicine, St. Louis, Missouri. Electronic address: aschaffer@path.wustl.edu.
authors.forename: András
authors.initials: A
authors.lastname: Schaffer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003872:Dermatitis / Q000175:diagnosis / Q000276:immunology*; D005260:Female; D050990:GATA3 Transcription Factor / Q000096:biosynthesis*; D006801:Humans; D016410:Lymphoma, T-Cell, Cutaneous / Q000175:diagnosis / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000175:diagnosis / Q000276:immunology*; D020825:T-Box Domain Proteins / Q000096:biosynthesis*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D055815:Young Adult; D000098815:T-bet Transcription Factor
chemical_list: D050990:GATA3 Transcription Factor; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor
keywords: GATA-3; Sezary syndrome; T helper cell; T-bet; anaplastic large cell lymphoma; cutaneous lymphoma; mycosis fungoides