MIB-1 immunohistochemical staining in selected tumours. A. Meningothelial meningioma. The digital image of the microscopic field showing scanty immunoreactive cells (brown nuclei marked with “+”). Low proliferative activity (Ki-67 LI - 1%) corresponds with the histological tumour grade I. B. Anaplastic oligodendroglioma. The digital image presenting numerous immunoreactive tumour cells assessed with the CAMI software as 21,5% (Ki-67 LI) which support the diagnosis of anaplastic (grade III) oligodendroglioma.