Prediction of recurrence in meningiomas after surgical treatment. A quantitative approach.

The prognostic significance of nuclear count, nuclear area fraction, and mean nuclear area estimated by automatic image analysis was evaluated in benign meningiomas. One hundred thirty-two meningiomas without recurrences, 39 meningiomas that recurred, and 40 first recurrences were examined. The tumors were classified according to age and sex of patients, localization, and histology; and the correlation between these parameters and the recurrence rate was assessed. The nuclear counts were identical in paraffin sections from meningiomas without recurrences (6.1 nuclei per 1,000 micrometer 2) and in meningiomas that recurred (6.4 nuclei per 1,000 micrometer 2). The cell count in the recurrences (7.4 nuclei per 1,000 micrometer 2) was higher than in the primary tumors. The same relationship was found for the nuclear area fractions, which were identical in meningiomas without recurrences and in primary meningiomas that recurred. The nuclear area fraction was increased in recurrences. The mean nuclear areas were identical in all groups. The histological type was of little significance in prediction of recurrence rate, although bone invasion and necrosis were of some significance. We found a higher recurrence rate in parasagittal meningiomas. Meningiomas that recurred appeared in a younger age group than other meningiomas, and the recurrence rate was higher for males than for females.