Immunohistochemical study of malignant melanoma.

Fifty-two malignant melanoma cases were divided morphologically into round, spindle and mixed-cell types and were studied immunohistochemically on the localization and staining intensity of S-100 protein and neuron specific enolase (NSE). Most of malignant melanomas were positively stained for S-100 protein and NSE. There were no correlation between the localization of S-100 protein and three cell types. However S-100 protein and degree of melanin production seemed to have an inverse relationship. On the other hand, for NSE, there were some differences on immunostaining intensity among the three cell types. Especially, deeply invasive melanomas showed strong reactivities for NSE and it may clinicopathologically indicate their poorer prognosis.