Correlation of histopathological characteristics with staining patterns in human melanoma assessed by (monoclonal) antibodies reactive on paraffin sections.

In order to investigate their possible role as prognostic markers, staining with the antibodies NKI/C-3 and anti-S100, that are applicable on paraffin sections, was examined using a group of primary cutaneous melanomas and autologous metastases using the immunoperoxidase procedure. All melanoma lesions stained with anti-S100, and the large majority with NKI/C-3. In primary melanomas showing a moderate or dense associated lymphocytic infiltrate, significantly more tumour cells stained with anti-S100 than in primary melanomas with a slight or absent infiltrate. In markedly pigmented metastases, significantly more tumour cells stained with NKI/C-3 than in less pigmented lesions; in primary melanomas this phenomenon just failed to be significant. In metastases with a high mitotic index a significantly lower proportion of tumour cells stained with NKI/C-3 than in lesions with a low mitotic index. No significant differences in staining were found between a group of primary melanomas with metastases and a group without metastases within a follow-up period of 5 years. Therefore, although staining with NKI/C-3 and anti-S100 appears to be associated with certain histopathological characteristics, it has no direct contribution to the assessment of prognosis in primary melanoma.