title: Langerhans cells in various benign and malignant pigment-cell lesions of the skin.
abstract: We used immunohistochemistry to study Langerhans cells (LCs) and the composition of the dermal inflammatory infiltrate both in normal skin and in biopsies from various benign and malignant pigment-cell lesions. In normal skin and most benign pigment-cell lesions, epidermal LCs are regularly distributed. OKT6-Positive cells outnumber the OKIa-positive cells. The inconspicuous dermal infiltrate studied in these biopsies was composed of helper and suppressor/cytotoxic T cells and some dermal LCs. More epidermal LCs with an abnormal cytologic presentation were found in a halo naevus and in the radial growth part of primary malignant melanomas. This finding was associated with a dermal infiltrate composed of suppressor/cytotoxic T cells, suggesting a defense mechanism of the host towards abnormal melanocytes. Epidermal LCs were rare in the central part of the biopsies which showed a primary malignant melanoma in its vertical growth. A dermal inflammatory infiltrate was absent in that area. These findings are interpreted as the morphologic expression of a damaged immune system.
mesh_terms: D000911:Antibodies, Monoclonal; D006801:Humans; D007801:Langerhans Cells / Q000276:immunology / Q000473:pathology*; D007911:Lentigo / Q000473:pathology; D008545:Melanoma / Q000473:pathology; D009508:Nevus, Pigmented / Q000473:pathology; D012878:Skin Neoplasms / Q000276:immunology / Q000473:pathology*; D013602:T-Lymphocytes, Cytotoxic / Q000473:pathology; D006377:T-Lymphocytes, Helper-Inducer / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal