title: hTERT expression in melanocytic lesions: an immunohistochemical study on paraffin-embedded tissue.
abstract: BACKGROUND
  Telomerase plays a role in the immortalization of cells and carcinogenesis. Previous studies have yielded conflicting results on whether human telomerase RNA (hTER) expression differs in nevi, atypical nevi and melanomas using polymerase chain reaction-based telomeric repeat amplification protocol or in situ hybridization assays. The aim of this study was to evaluate human telomerase reverse transcriptase (hTERT) staining in melanocytic lesions on paraffin-embedded tissues.
  
  
  METHODS
  Paraffin-embedded sections from 12 acquired nevi, seven dysplastic nevi, 11 Spitz nevi, eight primary invasive melanomas, and three metastatic melanomas were studied for staining intensity (0-3+) and percentage of labeled cells with anti-hTERT.
  
  
  RESULTS
  hTERT staining was observed in most cells (>75%), in all but three lesions, and was of greater intensity in the nucleus, especially the nucleolus, compared with the cytoplasm. Spitz nevi tended to have weaker hTERT staining (mean = 1.7) compared with acquired nevi (mean = 2.2), dysplastic nevi (mean = 2.4), primary melanomas (mean = 2.4), or metastatic melanomas (mean = 3).
  
  
  CONCLUSIONS
  Although telomerase activity was weaker in Spitz nevi, there was overlap with other nevi and primary invasive melanomas in our small series. Thus, hTERT expression does not appear to be a reliable adjunct to the histological diagnosis of primary melanocytic lesions.
authors.affiliation: Department of Pathology, University of Michigan Medical Center, 1301 Catherine, Ann Arbor, MI 48109-0602, USA. dfullen@umich.edu
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Fullen
authors.forename: Weijian
authors.initials: W
authors.lastname: Zhu
authors.forename: Dafydd
authors.initials: D
authors.lastname: Thomas
authors.forename: Lyndon D
authors.initials: LD
authors.lastname: Su
mesh_terms: D002467:Cell Nucleus / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000032:analysis*; D003937:Diagnosis, Differential; D004416:Dysplastic Nevus Syndrome / Q000175:diagnosis / Q000201:enzymology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008544:Melanocytes / Q000201:enzymology* / Q000473:pathology; D008545:Melanoma / Q000175:diagnosis / Q000201:enzymology* / Q000473:pathology / Q000556:secondary; D009506:Nevus / Q000737:chemistry* / Q000175:diagnosis / Q000473:pathology; D018332:Nevus, Epithelioid and Spindle Cell / Q000175:diagnosis / Q000201:enzymology* / Q000473:pathology; D009508:Nevus, Pigmented / Q000175:diagnosis / Q000201:enzymology* / Q000473:pathology; D016612:Paraffin Embedding; D015203:Reproducibility of Results; D012867:Skin / Q000201:enzymology / Q000473:pathology; D019098:Telomerase / Q000032:analysis*
chemical_list: D004268:DNA-Binding Proteins; D019098:Telomerase