[Microscopic identification of melanoma metastases in occult primary tumor]

A case of the metastasis of the tumor with a high degree of anaplasia to the neck lymph nodes is described. Histological features of the neoplasm--a combination of the epithelial-like and fusiform cells, alveolar and individual character of their surrounding by the argyrophil fibers and the presence of fine argyrophil granules in Paskal silvering--allowed to suspect the metastasis of pigment-free malignant melanoma, and to select a small panel of antibodies for immunohistochemical analysis. The expression by the tumor cells of vimentin, S-100 protein and melanoma antigen proved this tumor to be a malignant melanoma metastasis. Location of the primary tumor has not been revealed.