A clinicopathological study of the significance of the proportion of choroid morphology in chordoid meningioma.

Chordoid meningiomas (CM) account for approximately 0.5% to 1.0% of intracranial meningiomas. This tumor has a strong risk of recurrence and aggressive growth (World Health Organization grade II). Histological analysis of CM tumors shows that the tissue is often dominated by chordoid morphology; however, the exact relationship between the percentage of the chordoid component and other clinicopathological features is unknown. We collected 26 surgical specimens from 17 patients who had a histological diagnosis of CM between January 1986 and June 2010. The chordoid elements constituted 30% to 98% of the area of the tumor. In 12 of 17 (70.6%) primary tumors, over 50% of the area displayed the chordoid pattern. Recurrence was noted in nine of these patients and five underwent a second operation. These five patients showed a histopathological progression of aggressive features. The proportion of chordoid elements in each recurrent tumor also increased. Thus, the chordoid proportion in CM is associated with a greater likelihood of recurrence.