Prediction of Histological Grade and Completeness of Resection of Intracranial Meningiomas: Role of Peritumoural Brain Edema.

BACKGROUND Meningioma is the commonest primary intracranial tumour in adults. Excision is curative for low grade meningioma, whereas high-grade meningioma requires adjuvant therapy following surgery. Several studies have examined the association between peritumoural brain Edema - a common feature in meningioma - and histological grading with mixed results. The present study attempted to elucidate this association and if peritumoural brain Edema affects the intra-operative judgement of surgeons on the completeness of resection. METHODS An observational study was conducted among those who underwent surgery for meningioma. Eighteen subjects were recruited each for low- and high-grades, respectively. Magnetic resonance imaging (MRI) prior to surgery was employed for interpreting the Edema index and MRI after surgery was used to determine residual tumour. RESULTS Median age was 50 years, male to female ratio was 1:3.5, 69.4% had peritumoural brain Edema and 75% had reported gross resection. Among the reported gross total resection cases, 40.7% had residual tumour. Analysis showed statistically significant association between peritumoural brain Edema (P = 0.027) and tumour volume (P = 0.001) with high-grade meningioma, however multivariate analysis did not present any association. No association was noted between judgement of tumour resection by surgeons and peritumoural brain Edema. CONCLUSION Odds ratio for peritumoural brain Edema remained high and the tumour volume exhibited marginal P-value marginal significance for prediction of high grade meningioma. These two factors may still contribute to the tumour grade and should be included in further studies on the prognosis of meningioma.