IMMUNOCYTOCHEMICAL DIAGNOSIS OF AMELANOTIC METASTATIC MELANOMA USING MONOCLONAL-ANTIBODIES HMB-45 AND EP1-3

The analysis of fine-needle aspirates and effusions has proved to be a valuable tool for the cytological identification of metastatic melano ma. Nevertheless, while malignant pigmented cells can be easily detect ed on cytological specimens, their identification may be very difficul t in patients bearing amelanotic lesions. In the present study we have evaluated whether this limitation can be overcome using two monoclona l antibodies (mAbs) HMB45 and Ep1-3, which are highly specific for the melanocyte lineage. These reagents were assayed in immunocytochemical tests performed on cytological material obtained from 50 patients wit h a past history of melanoma and 463 bearing metastases from a cryptic primary tumour. These mAbs, employed in combination with a panel of m onoclonal reagents with well-defined tumour specificity, may improve t he accuracy of the conventional cytopathological diagnosis of melanoma metastases in the two groups of patients.