MKI67 and benign meningioma: The Ki-67 LI is about 1% to 4% for benign meningioma and about 10% to 15% for anaplastic meningioma.[5] In this case, it was estimated that the malignancy and recurrence rates were high, as the Ki-67 LIs were 52.3% in the primary lesion and 40% in the metastatic lung lesion.