title: Tenascin expression in actinic keratosis.
abstract: BACKGROUND
  Tenascin is an extracellular matrix protein frequently expressed around neoplastic and non-neoplastic lesions of the skin. Actinic keratoses (AKs) are intraepidermal neoplastic lesions of the sun-exposed skin. They are classified according to the extension of dysplasia in four stages; they also present different histological varieties.
  
  
  METHODS
  We performed an immunohistochemical study using tenascin monoclonal antibody diluted 1 : 50 on 150 cases of AKs classified, respectively, in histotypes (38 hypertrophic, 18 atrophic, 21 bowenoid, 19 acantolytic, and 40 mixed) and in stages (27 stage I, 46 stage II, 42 stage III, and 35 stage IV; 14 in tumoral progression).
  
  
  RESULTS
  Tenascin positivity was observed in all cases at the dermal level close to the epithelial lesion. The intensity of reaction increased from stage I to stage IV and, of course, also in tumoral progression. Its expression was not related to the histotypes. In very few cases, the atypical keratinocytes were positive.
  
  
  CONCLUSIONS
  Tenascin expression in AKs is related to the stages of dysplasia. In fact, the immunostaining intensity corresponds to the degree of the dysplasia rather than the thickness of the involved epidermis. Tenascin plays a role in neoplastic progression working as an anti-adhesive factor.
authors.affiliation: Dipartimento di Patologia Umana, Policlinico Universitario Pad.D, 98124 Messina, Italia. maria.lentini@unime.it
authors.forename: Maria
authors.initials: M
authors.lastname: Lentini
authors.forename: Carmelo
authors.initials: C
authors.lastname: Schepis
authors.forename: Domenica Anna
authors.initials: DA
authors.lastname: Cuppari
authors.forename: Dario
authors.initials: D
authors.lastname: Batolo
mesh_terms: D000199:Actins / Q000378:metabolism*; D002448:Cell Adhesion; D002471:Cell Transformation, Neoplastic; D018450:Disease Progression; D004817:Epidermis / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000378:metabolism / Q000473:pathology; D007642:Keratosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012720:Severity of Illness Index; D019063:Tenascin / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D019063:Tenascin