[Primary tissue culture of nevus cell nevus--in comparison with the findings from neurofibroma culture].

Forty-two nevus cell nevi excised surgically from 40 patients were processed for primary culture. The characteristic features of cultured nevi were compared with those of neurofibroma reported previously. 1) Based on phase-microscopic findings, S-100 protein staining, and slow motion picture, most of the cultured macrophage-like cells or cells with dendrites were considered to be nevocytes. 2) The emigration of nevocytes was observed in 31 of the 42 nevus cultures (73%). Nevocytes classified histologically as the intradermal type with fatty degeneration and nevi obtained from the face and aged patients exhibited higher tendencies to ward emigration when they were cultured. 3) The cultured Schwann cells in neurofibroma and the nevus cell nevus, mainly c-type nevocytes, are both of neural crest origin. They were observed to have closely similar morphological and S-100 protein staining features.