[Monoclonal antibodies in pigmented lesions].

We have applied a battery of murine monoclonal antibodies (R-24, L-101, S-171) to the immunohistological diagnosis of 35 pigmented lesions. The results of our study allow us to conclude that: 1) The monoclonal antibody R-24 is a good marker of normal and neoplastic melanocytes, although some melanomas do not stain with this monoclonal antibody. The application of R-24 may contribute to the pathologic differential diagnosis of melanoma metastases. 2) The association of R-24+ and L-101+ staining is found in melanocytic nevus as well as in melanomas, and do not allow the differential diagnosis between them. 3) Stains with R-24, L-101 and S-171 are simultaneously positive only in melanomas, and with low frequency.