CD68 and neoplasm: The MIB-1 assessment in meningiomas seems to be reproducible in an uniform intra-lab setting; (2) MIB-1 labeling indices of both primary and their corresponding recurrent meningioma as well as diffuse CD68+ macrophage infiltrates are significantly and inversely correlated with the time to recurrence of cranial WHO grade 1 and 2 meningiomas; and (3) male patients, patients having a low plasma fibrinogen level or harboring diffuse CD68+ macrophage infiltrates within the tumor tissue might have a progressive course of cellular proliferative potential in locally recurrent meningiomas.