title: Defining early mycosis fungoides: validation of a diagnostic algorithm proposed by the International Society for Cutaneous Lymphomas.
abstract: BACKGROUND
  Mycosis fungoides (MF) is the most common subtype of cutaneous T-cell lymphoma and is often difficult to diagnose. Early-stage disease is particularly challenging and requires clinical and histopathologic correlation to make an accurate diagnosis. In order to facilitate the diagnosis of early MF, an algorithm has been proposed by the International Society for Cutaneous Lymphomas (ISCL) whereby clinical and histopathologic characteristics as well as immunohistochemistry and T-cell receptor gene rearrangement studies may be applied to suspected cases of MF. The diagnostic utility of this algorithm has not yet been validated. We sought to determine the validity of the proposed algorithm via an investigator-blinded, retrospective, case-control study.
  
  
  METHODS
  A total of 34 cases were randomly selected from the database of a clinic for cutaneous T-cell lymphomas and included patients with MF and patients with clinicopathologic mimics. The proposed diagnostic algorithm was systematically applied to the entire cohort. Each case was assigned a composite score based on the parameters in the proposed algorithm.
  
  
  RESULTS
  Among the 24 cases of MF, 21 cases achieved four or more points through application of the algorithm. Among the 10 cases of MF mimics, only four achieved four or more points. This difference was significant (Fisher's exact test, p = 0.009). The sensitivity of the 4-point threshold for a diagnosis of MF was 87.5% and the specificity was 60%.
  
  
  CONCLUSIONS
  The diagnostic algorithm proposed by the ISCL is a statistically valid method for defining cases of early MF and distinguishing these cases from other benign dermatoses. However, the clinical utility of the algorithm may be limited by its low specificity. Further refinement of the algorithm may improve its accuracy.
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Travis
authors.initials: T
authors.lastname: Vandergriff
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Kaveh A
authors.initials: KA
authors.lastname: Nezafati
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Susa
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Karai
authors.affiliation: Veterans Affairs Hospital, Sierra Nevada Health Care System, Reno, NV, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Sanguinetti
authors.affiliation: Department of Clinical Science, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Hynan
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Ambruzs
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Dwight H
authors.initials: DH
authors.lastname: Oliver
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Amit G
authors.initials: AG
authors.lastname: Pandya
mesh_terms: D000465:Algorithms; D001706:Biopsy; D016022:Case-Control Studies; D055088:Early Detection of Cancer / Q000379:methods / Q000592:standards; D019672:Genes, T-Cell Receptor; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D016410:Lymphoma, T-Cell, Cutaneous / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D009182:Mycosis Fungoides / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology / Q000473:pathology
keywords: algorithm; clinicopathologic correlation; cutaneous T-cell lymphoma; histopathology; mycosis fungoides