B3GAT1 and plexiform neurofibroma: Reactivity for CD57 evidencing nerve fascicles were found within neurofibromas (Fig. 2A), diffuse and high quantity of positive cells in PENs (Fig. 2B), nerve fascicles and rare cells in GCTs (< 5%) (Fig. 2C), and infrequent in neoplastic cells of schwannomas (Fig. 2D).