DIFFERENTIAL EXPRESSION OF CERBB3 IN NEVI AND MALIGNANT MELANOMAS

28 naevi, 43 malignant melanomas and 16 lymph nodes with melanoma meta stases were stained immunohistochemically for the expression of cerbB3 oncoprotein using antibody RTJ1. Positive reaction was found in 60% o f naevi and in 25% of melanoma eases. The difference in frequency of t he reaction occurence between naevi and melanomas was statistically hi ghly significant (p=0.0017). In naevi, the percentage of cerbB3 positi ve cells (56.5%) was also significantly higher (p=0.021) as compared w ith that of melanomas (37%). The cerbB3 positive cells were found only in cases without metastases. Positive reaction was also observed in 4 out of 16 investigated lymph nones with melanoma metastases. The role of cerbB3 in the development of melanoma is discussed.