Melanocyte mutation in halo naevus and malignant melanoma?

Halo naevus cells on frozen sections react with sera from patients with benign halo naevus or with malignant melanoma. Halo naevus cells also react with our specifically absorbed heterologous antihuman malignant melanoma antiserum (RAMMA). Since the cytoplasm of all the naevus cells within the halo naevus react with sera from patients with malignant melanoma, this implies that the entire population of melanocytic cells in the mole has undergone mutation, because non-pathological skin melanocytes do not react.