The effect of melanin bleaching on immunohistochemical staining in heavily pigmented melanocytic neoplasms.
The accumulation of excessive amounts of melanin in melanocytic lesions can obscure cellular morphology and can further hinder immunocytochemical procedures. We have used a modification of the potassium permanganate/oxalic acid melanin-bleaching technique, involving much reduced bleaching times, in order to remove melanin granules prior to incubation with primary antibody. We have assessed a panel of antibodies applicable to the evaluation of melanocytic lesions and in addition have also assessed antibodies that may be more useful in research. The study attempts to determine which antigens may be affected by bleaching and which are not. Antigens S100, HMB 45, NKIC3, CD34, and L26 are relatively unaffected by this procedure. Factor-VIII-related antigen and vimentin and CD68 antigens produced enhanced staining. In contrast, antigens CD3, CD31, and CD45RO were abolished. In addition, smooth muscle actin and desmin antigens demonstrated considerable nonspecific background staining and were not reliable in this study. This technique demonstrates that a fairly wide range of antigens are preserved after bleaching and that distinction between melanocytes and melanophages can reliably be performed using the conventional immunocytochemical chromogen 3,3-diaminobenzidine and without the need for elaborate counterstaining.
Department of Dermatopathology, St. John's Dermatology Centre, St. Thomas' Hospital, London, U.K.
G E
GE
Orchard
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Calonje
D000199:Actins / Q000187:drug effects / Q000378:metabolism; D015703:Antigens, CD / Q000187:drug effects / Q000378:metabolism; D018951:Antigens, CD20 / Q000187:drug effects / Q000378:metabolism; D018952:Antigens, CD34 / Q000187:drug effects / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000187:drug effects / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D017252:CD3 Complex / Q000187:drug effects / Q000378:metabolism; D003893:Desmin / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D017493:Leukocyte Common Antigens / Q000187:drug effects / Q000378:metabolism; D008543:Melanins / Q000378:metabolism; D008545:Melanoma / Q000737:chemistry* / Q000276:immunology; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins / Q000187:drug effects / Q000378:metabolism; D010070:Oxalates / Q000494:pharmacology; D010084:Oxidation-Reduction; D010858:Pigmentation / Q000187:drug effects*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism; D011196:Potassium Permanganate / Q000494:pharmacology; D015203:Reproducibility of Results; D009418:S100 Proteins / Q000187:drug effects / Q000378:metabolism; D012680:Sensitivity and Specificity; D012867:Skin / Q000737:chemistry / Q000187:drug effects / Q000276:immunology; D012878:Skin Neoplasms / Q000737:chemistry* / Q000276:immunology; D014746:Vimentin / Q000187:drug effects / Q000378:metabolism; D014841:von Willebrand Factor / Q000187:drug effects / Q000378:metabolism; D000097382:CD68 Molecule
D000199:Actins; D015703:Antigens, CD; D018951:Antigens, CD20; D018952:Antigens, CD34; D015214:Antigens, Differentiation, Myelomonocytic; D000951:Antigens, Neoplasm; D017252:CD3 Complex; D003893:Desmin; D017493:Leukocyte Common Antigens; D008543:Melanins; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D010070:Oxalates; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011196:Potassium Permanganate; D009418:S100 Proteins; D014746:Vimentin; D014841:von Willebrand Factor; C067980:CD68 antigen, human; D000097382:CD68 Molecule