S100B and neoplasm: We chose the 5 gonadotroph tumours based on the percentages of S100B + cells: 4 tumours having a heterogeneous distribution, including the tumour having the widest spread of the percentages of S100B + cells—gonadotroph tumour #3, and one tumour having homogeneous percentages of S100B + cells—gonadotroph tumour #18.