title: Expression of stem cell markers nestin and cytokeratin 15 and 19 in cutaneous malignancies.
abstract: BACKGROUND
  Emerging evidence is implicating stem cells in the pathogenesis of different cutaneous neoplasms. The immunohistochemical use of stem cell markers has facilitated stem cell identification. While few studies have examined the expression of cytokertatin (CK)15 and cytokeratin (CK)19 in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), only rarely have nestin expression been examined in these two malignancies. Furthermore, stem cell marker expression, to the best of our knowledge, has not been examined in Merkel cell carcinoma (MCC).
  
  
  METHODS
  In this study, we examined the expression of stem cell markers CK15, CK19 and nestin in 51 overall cases (11 cases of MCC and 20 cases each of BCC and SCC) retrieved from the pathology files of Skin Pathology Laboratory, Boston University School of Medicine.
  
  
  RESULTS
  Cytokeratin 15 immunoreactivity was observed in 30% of BCC cases and only a single (5%) SCC case, while all MCC cases were negative. While 60% of BCC cases and 30% of SCC cases stained positively with CK19, all MCC cases showed positive immunostaining in a dot-like pattern. While negative in BCC and MCC, nestin expression was interestingly seen in 45% of SCC cases.
  
  
  CONCLUSIONS
  Our study described the expression profiles of stem cell markers CK15, CK19 and nestin in BCC, SCC and MCC. In addition to confirming results of the previous reports, our study also showed positive nestin expression in around half of SCC cases, which adds this malignancy to the cutaneous tumours that have been so far reported to exhibit nestin expression.
authors.affiliation: Dermatopathology Section, Department of Dermatology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: O
authors.initials: O
authors.lastname: Abbas
authors.forename: J
authors.initials: J
authors.lastname: Bhawan
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D002280:Basal Cell Carcinoma / Q000378:metabolism* / Q000473:pathology; D015266:Carcinoma, Merkel Cell / Q000378:metabolism* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007381:Intermediate Filament Proteins / Q000378:metabolism*; D053569:Keratin-15 / Q000378:metabolism*; D053539:Keratin-19 / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D064231:Nestin; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D007381:Intermediate Filament Proteins; D053569:Keratin-15; D053539:Keratin-19; C577484:NES protein, human; D009419:Nerve Tissue Proteins; D064231:Nestin