[Monoclonal antibody HMB-45 in diagnosis of intra-ocular melanoma]

69 eyes, which had to be enucleated because of an uveal melanoma, were investigated immunohistologically. HMB-45-antigen, which is supposed to be highly specific for melanocytic tumours, was found in 68 cases (sensitivity 99%) with a monoclonal antibody. S 100-antigen was positive in 63 cases (sensitivity 91%) using a polyclonal antibody. The addition of HMB-45-immunohistochemistry to routine histological diagnostic procedures is valuable, when a non-melanocytic uveal tumour cannot be ruled out or when the degree of melanoma-invasion has to be determined with greater accuracy. At the site of melanoma-invasion changes of cellular reactivity seem to occur, as 11 of the 69 studied tumours (16%) showed an increased HMB-45-expression in this area. HMB-45-antigen was detectable even in paraffin embedded material obtained from eyes enucleated 30 years ago.