Neuropathological Characterization of Meningioma

Neuropathological classification was performed based on the 2016 WHO criteria [3 (link)]. All histopathological reports underwent repeated examination to confirm that diagnosis was in line with these requirements. Immunohistochemistry was performed in the same workflow as described before for paraffin-embedded biopsy tissue specimen [31 (link),32 (link)]. The MIB-1 labeling index was investigated using the following antibody: Anti-Ki67 (Clone 2B11 + PD7/26). Moreover, semiquantitative analysis and scoring of the CD68⁺ stainings using anti-CD68 antibodies to detect macrophages were performed (Clone KP1, dilution 1:1000, DAKO, Glostrup, Denmark). As previously described, meningioma specimens were investigated for the absence, focal or diffuse staining of CD68⁺ macrophages [33 (link)]. Visualization was performed using diaminobenzidine and a neuropathological examination was performed by expert neuropathologists including A.J.B.