title: Acquired elastotic hemangioma-like changes and eccrine sweat duct squamous metaplasia in lichen simplex chronicus/prurigo nodularis-like lesions of the knee and elbow.
abstract: BACKGROUND
  The so-called acquired elastotic hemangioma (AEH) represents a peculiar vascular lesion affecting the sun-damaged skin of the extensor surface of the forearms or the lateral aspect of the neck of middle-aged or elderly women.
  
  
  METHODS
  This is a clinicopathological and immunohistochemical study of a series of 6 lesions located on the knee or elbow showing epithelial features of lichen simplex chronicus (LSC)/prurigo nodularis (PN) with a marked subepidermal vascular proliferation closely resembling AEH.
  
  
  RESULTS
  Microscopically, all cases of cutaneous lesions showed epithelial features of LSC/PN, that is compact hyperkeratosis with focal parakeratosis, irregular acanthosis, prominent hypergranulosis. Moreover, a marked subepidermal vascular proliferation arranged in a horizontal band closely resembling AEH was detected in these lesions. Another common histopathological finding was eccrine duct squamous metaplasia and/or hyperplasia.
  
  
  CONCLUSIONS
  While AEH represents a distinctive clinicopathological variant of hemangioma characteristically appearing on sun-exposed areas of middle-aged or elderly patients, the herein described lesions seem to be non-neoplastic epithelial, vascular and eccrine sweat duct reactive changes which are likely to be associated with chronic pressure or repeated mechanical stimulation with a marked predilection for the knee and elbow.
authors.affiliation: Sikl's Department of Pathology, Charles University in Prague, Medical Faculty in Pilsen, Pilsen, Czech Republic.|Bioptical Laboratory, Pilsen, Czech Republic.
authors.forename: Denisa
authors.initials: D
authors.lastname: Kacerovska
authors.affiliation: Department for Health Promotion and Mother and Child's Care G. D'Alessandro, Section of Pathology, University of Palermo, Palermo, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Portelli
authors.affiliation: Sikl's Department of Pathology, Charles University in Prague, Medical Faculty in Pilsen, Pilsen, Czech Republic.|Bioptical Laboratory, Pilsen, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Michal
authors.affiliation: Sikl's Department of Pathology, Charles University in Prague, Medical Faculty in Pilsen, Pilsen, Czech Republic.|Bioptical Laboratory, Pilsen, Czech Republic.
authors.forename: Dmitry V
authors.identifier: http://orcid.org/0000-0003-1893-535X
authors.initials: DV
authors.lastname: Kazakov
keywords: acquired elastotic hemangioma-like; eccrine sweat ducts; elbow; knee; lichen simplex chronicus; prurigo nodularis; squamous metaplasia