Serum levels of S-100 protein are directly proportional to the size, number, thickness and degree of cellularity of congenital melanocytic nevi

Abstract

To the Editor: Some patients with congenital melanocytic nevi (CMN) present progressive growth and thickening, extracutaneous involvement (neurocutaneous melanocytosis, NCM) or neoplastic transformation (melanoma); and others remain stable or even regress. There are no markers to assess progression or follow-up. Recently, we found S-100, a protein which acts on cell differentiation and proliferation, elevated in CMN.1 S-100 is a ligand of the RAGE pathway (related to the MAPK-pathway), and low serum levels of soluble-RAGE were related to poor survival in melanoma.2 Also SOX10, expressed in melanocytes with high specificity, is useful in detection, prognosis and treatment assessment of melanoma.3 We explored if S-100, RAGE and SOX10 serum levels vary in children’s CMN and assessed clinical or pathological correlations.