title: An immunohistochemical study of angiokeratomas of children.
abstract: BACKGROUND
  Angiokeratomas are vascular anomalies in which the clinical, histological, and immunohistochemical characteristics are insufficient to determine whether the lesion is a vascular neoplasm or vascular malformation, and their exact origin is also uncertain. To further clarify the nosology of angiokeratomas, we studied 14 cases.
  
  
  OBJECTIVE
  To analyze immunohistochemical characteristics of angiokeratomas to gain further insight into its histogenesis.
  
  
  METHODS
  We carried out a retrospective review of the histopathology files. Immunohistochemical expression for Wilms tumor 1 (WT1), GLUT1, D2-40, podoplanin, Prox1, and ERG1 was performed in 14 cases.
  
  
  RESULTS
  None of the lesions showed cytoplasmic immunoreactivity for WT1. GLUT1 resulted to be negative in 13 cases. All 14 cases in our series showed some expression with at least 1 lymphatic marker. In 12 cases, the positivity was diffuse and strong for ERG1.
  
  
  CONCLUSIONS
  Angiokeratomas are complex lesions with difficult classification. Angiokeratomas are best considered vascular malformations in children, according to the WT1-negative stain. The lymphatic component of angiokeratoma is demonstrated by positivity and/or focal expression for lymphatic markers (podoplanin and Prox1); however, a blood capillary component within the malformation cannot be excluded.
authors.affiliation: *Department of Dermatology, Hospital de Cascais Dr. José de Almeida, Lisbon, Portugal; †Department of Dermatology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain; ‡Dermatohistopathologische Gemeinschaftslabor, Friedrichshafen, Germany; §Department of Dermatology, Fundación Jiménez Díaz, Madrid, Spain; ¶Department of Dermatology, Hospital Universitário de Coimbra, Coimbra, Portugal; and ‖Department of Pathology, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.
authors.forename: Felicidade
authors.initials: F
authors.lastname: Trindade
authors.forename: Antonio
authors.initials: A
authors.lastname: Torrelo
authors.forename: Heinz
authors.initials: H
authors.lastname: Kutzner
authors.forename: Luis
authors.initials: L
authors.lastname: Requena
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Tellechea
authors.forename: Isabel
authors.initials: I
authors.lastname: Colmenero
mesh_terms: D000293:Adolescent; D000794:Angiokeratoma / Q000145:classification* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D006801:Humans; D007150:Immunohistochemistry; D042601:Lymphatic Vessels / Q000002:abnormalities*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000145:classification* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor