title: Immunostain use in the diagnosis of melanomas referred to a tertiary medical center: a 15-year retrospective review (2001-2015).
abstract: BACKGROUND
  Little is known regarding the clinical practice of immunohistochemistry in the diagnosis of melanoma. We aimed to assess the incidence of immunostain usage by referring pathologists and dermatopathologists in melanoma cases sent for consultative review. As a secondary objective, associations between immunostain use and specific melanoma characteristics were also evaluated.
  
  
  METHODS
  This is a retrospective review of consultation reports of referred melanomas at a tertiary academic center in New York, NY from 2001 to 2015. Univariate regression analysis was performed on melanomas with accompanying immunostains and on characteristics such as Breslow's depth, location, prognostic factors and morphologic subtypes. Associations between immunostain usage and these characteristics were analyzed using Fisher's exact test.
  
  
  RESULTS
  Immunostain use significantly increased over the study period (p < 0.001) and was more likely to be associated with melanomas that were thicker [odds ratio (OR) = 2.5; 1.7-3.6]; located on the head and neck (OR = 1.6; 1.4-1.9) or acral sites (OR = 1.5; 1.1-2.0); had ulceration (OR = 2.1; 1.6-2.8), dermal mitoses (OR = 1.3; 1.1-1.5), or perineural invasion (OR = 3.6; 2.0-6.5); or were of desmoplastic (OR = 7.4; 4.5-12), amelanotic (OR = 7.1; 3.6-14), or nevoid subtypes (OR = 4.0; 1.7-8.9).
  
  
  CONCLUSIONS
  Immunostain use in the diagnosis of melanoma has increased significantly in the past 15 years for reasons that remain unclear.
authors.affiliation: Dermatopathology Section, The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY, USA.
authors.forename: Randie H
authors.initials: RH
authors.lastname: Kim
authors.affiliation: Dermatopathology Section, The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY, USA.
authors.forename: Shane A
authors.initials: SA
authors.lastname: Meehan
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry / Q000706:statistics & numerical data*; D008545:Melanoma / Q000175:diagnosis*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor
keywords: dermatopathology; epidemiology; immunohistochemistry; melanoma; practice trends