title: Quantitative comparison of MiTF, Melan-A, HMB-45 and Mel-5 in solar lentigines and melanoma in situ.
abstract: BACKGROUND
  It is often challenging to reliably assess the number of lesional melanocytes in intraepidermal melanocytic proliferations involving sun-damaged skin. Therefore, dermatopathologists routinely use immunostains to help differentiate melanocytes from surrounding keratinocytes.
  
  
  METHODS
  Forty-three cases of solar lentigo or melanoma in situ (of the lentigo maligna type) were retrospectively chosen (20 melanomas in situ and 23 solar lentigo). Microphthalmia transcription factor (MiTF), HMB-45, Melan-A and Mel-5 immunostains were performed with an Azure blue counterstain, and the mean melanocyte counts were calculated within a 1-mm segment of epidermis.
  
  
  RESULTS
  In solar lentigines, the mean melanocyte counts were 27 (MiTF), 23 (HMB-45 and Mel-5) and 41 (Melan-A), as compared to hematoxylin and eosin (H&E) (25). In melanoma in situ, the mean melanocyte counts were 112 (MiTF), 149 (Melan-A), 111 (HMB-45) and 80 (Mel-5), as compared to H&E (109).
  
  
  CONCLUSIONS
  These results show that Melan-A significantly overestimates the density of melanocytes within dermatoheliotic skin. Compared to other tested stains, nuclear staining MiTF allowed greater distinction of melanocytes from keratinocytes with melanized cytoplasm. These findings indicate that MiTF is a superior marker for quantification of melanocytes in the evaluation of subtle intraepidermal melanocytic proliferations and in the differential diagnosis of solar lentigo.
authors.affiliation: Department of Pathology, Stanford University, Stanford, CA 94305, USA. jinahkim@stanford.edu
authors.forename: Jinah
authors.initials: J
authors.lastname: Kim
authors.forename: Janis M
authors.initials: JM
authors.lastname: Taube
authors.forename: Timothy H
authors.initials: TH
authors.lastname: McCalmont
authors.forename: Earl J
authors.initials: EJ
authors.lastname: Glusac
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D002452:Cell Count; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism / Q000473:pathology; D007911:Lentigo / Q000175:diagnosis / Q000378:metabolism*; D058965:MART-1 Antigen / Q000378:metabolism*; D008297:Male; D008544:Melanocytes / Q000473:pathology; D008545:Melanoma / Q000175:diagnosis / Q000378:metabolism*; D058950:Melanoma-Specific Antigens / Q000378:metabolism*; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism*; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D058951:gp100 Melanoma Antigen
chemical_list: D014408:Biomarkers, Tumor; D006023:Glycoproteins; D058965:MART-1 Antigen; C094218:MEL-5 protein, human; C497234:MITF protein, human; C548667:MLANA protein, human; D058950:Melanoma-Specific Antigens; D051739:Microphthalmia-Associated Transcription Factor; C548637:PMEL protein, human; D058951:gp100 Melanoma Antigen