Intracranial meningiomas: analysis of recurrence after surgical treatment.

Recurrence of intracranial meningiomas after surgery has long been recognized, but there is still no consensus about factors responsible for recurrence. To better understand such factors, we analysed data on 276 patients with meningiomas who were treated at our institution from 1976 to 1990 (mean follow-up = 5.1 years). Effects of sex, tumour histology, tumour site, and radiotherapy on recurrence were closely studied. Using World Health Organization criteria to define malignancy, 254 of the tumours were benign and 22 were atypical or malignant. For data analysis, distinction was made between "recurrence"(i.e., reappearance of tumour after total resection) and "regrowth" (i.e., tumour enlargement after subtotal removal). Recurrence was seen in 2 of 183 benign meningiomas and in 10 of 16 malignant meningiomas. Recurrence and regrowth rates for malignant meningiomas far exceeded those for benign meningiomas (p = 0.001). Neither sex nor tumour site was associated with subsequent recurrences in patients whose tumours had been completely resected. The influence of radiotherapy was studied in terms of its effects on benign versus malignant meningiomas, whether given after complete or incomplete resection, and whether given after primary resection or on reoperation. We found that radiotherapy did not decrease "recurrence" or "regrowth" regardless of when administered, either at first resection or on recurrence. This was true for benign as well as malignant meningiomas. However, due to the small number in our series, we cannot conclude that radiotherapy has no beneficial role in the treatment of meningiomas.(ABSTRACT TRUNCATED AT 250 WORDS)