CLEAR-CELL MENINGIOMA VARIANT AND CLINICAL AGGRESSIVENESS

The few reports about clear cell meningiomas (CCM) point to an inordin ate clinical aggressiveness despite their histological benignity. We s tudied 5 CCM aiming to assess their clinicopathological, cytometric, a nd ultrastructural features. Two patients were females and 3 males, wi th a mean age of 36 years. Two tumors were spinal,one of the cerebral convexity, one of the tentorium-clinoid region, and one of the base of the skull. The first 3 were totally removed and have not recurred for a mean follow-up time of 40 months. The tentorium-clinoid and the sku ll base tumors had radical subtotal and partial resections, and recurr ed after 16 and 1.5 months, respectively. All tumors but one, a non-re current one, presented no signs of histological anaplasia. The prolife rative capacity, as assessed by MIB-1 staining index (SI), of recurren t tumors was slightly higher than that of those tumors that did not re cur. All cases showed DNA diploid pattern. Amianthoid-type fibers were disclosed on ultrastructural study. CCM arose in patients younger tha n those with other variants of meningioma, the spinal canal and the po sterior fossa were the common sites. Finally, intracranial tumors were linked to an aggressive behavior.