title: Standard immunostains for melanoma in sentinel lymph node specimens: which ones are most useful?
abstract: BACKGROUND
  Sentinel lymph node (SLN) biopsy in melanoma is an increasingly used procedure. Pathologic evaluation of SLNs using immunohistochemistry improves diagnostic accuracy, yet no universally accepted standard protocol for pathologic processing of SLNs exists.
  
  
  OBJECTIVE
  The primary purpose of this study was to evaluate our experience with the sensitivity of the immunostains S-100, HMB-45, and Melan-A for SLN biopsy.
  
  
  METHODS
  Ninety-nine positive SLNs from 72 patients were retrospectively reviewed for the presence of microscopic metastatic melanoma on hematoxylin and eosin (H&E), S-100, HMB-45, and Melan-A stained sections and sensitivities of each immunohistochemical stain were determined.
  
  
  RESULTS
  The sensitivities of S-100, HMB-45, and Melan-A were 97%, 75%, and 96% respectively.
  
  
  CONCLUSIONS
  Given the lower sensitivity of HMB-45, our practice for evaluation of SLN biopsy specimens was modified using combinations of H&E, S-100, and Melan-A without HMB-45. If the H&E sections are negative or equivocal for metastatic melanoma, immunohistochemistry staining with S-100 protein and Melan-A is performed. New and improved protocols will undoubtedly be forthcoming as the field advances.
authors.affiliation: Department of Dermatology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0314, USA. dariusjk@umich.edu
authors.forename: Darius J
authors.initials: DJ
authors.lastname: Karimipour
authors.forename: Lori
authors.initials: L
authors.lastname: Lowe
authors.forename: Lyndon
authors.initials: L
authors.lastname: Su
authors.forename: Ted
authors.initials: T
authors.lastname: Hamilton
authors.forename: Vernon
authors.initials: V
authors.lastname: Sondak
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Johnson
authors.forename: Douglas
authors.initials: D
authors.lastname: Fullen
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000737:chemistry* / Q000473:pathology; D008207:Lymphatic Metastasis; D058965:MART-1 Antigen; D008545:Melanoma / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary*; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins / Q000032:analysis; D009418:S100 Proteins / Q000032:analysis; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology*
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058965:MART-1 Antigen; C548667:MLANA protein, human; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D009418:S100 Proteins