Dissociation of HLA heavy chain and light chain (beta 2 microglobulin) expression on the cell surface of cutaneous malignancies.

Biopsies from twenty-nine malignant skin tumours and four benign dermatoses and fourteen samples of normal skin were stained for cell surface membrane or cytoplasmic expression of HLA heavy chain and light chain (beta 2 microglobulin) by use of the immunoperoxidase technique on frozen sections using monoclonal antibodies. Results showed a loss of beta 2 microglobulin from the surface of malignant cells in twenty-four out of twenty-nine cutaneous malignancies and the presence of HLA heavy chain in all twenty-nine primary and secondary tumours. Expression of both heavy and light chains was observed in the four benign lesions and in normal epidermis in all samples examined. This would appear to be the first report of dissociation of heavy and light HLA chain expression in various forms of cutaneous malignancy.