Neurone specific enolase and S100 protein as possible prognostic indicators in melanoma.

Fourteen cases of primary melanoma and 25 of their subsequent metastases were stained for Neurone Specific Enolase (NSE) and S100 protein. Intensity of staining for NSE and S100 protein broadly corresponded in 11 of the primary lesions and was disparate in three. Staining intensity for NSE or S100 was independent of tumour thickness. Primary lesions showing marked or moderate staining for NSE and S100 protein took a shorter time to metastasize than those showing slight or no staining. Assessment of staining intensity for NSE and S100 thus identified prognostic categories corresponding to disease free interval obtained by division according to tumour thickness. Staining intensity for S100 protein appears to give a clearer indication as to expectation of disease free interval. Staining intensity in individual cases showed an increase both for NSE and S100 protein between primary and metastatic lesions. The data presented are not sufficient to assign statistical significance but may lead to the incorporation of functional studies into the pathological assessment of malignant melanocytic lesions. The simultaneous occurrence of a functional neuronal and Schwann cell marker in melanoma is discussed.