Correlation between DNA Contents and Histopathologic Findings in Meningiomas

ABSTRACT

Intracranial meningioma is a common benign tumor. Although tumor mass might have been totally removed, aggravation of symptoms or recurrence of mass may sometimes be noticed. Histopathologic finding has been known as one of probable prognostic factors in meningiomas. In this study, correlation between DNA contents and histopathologic findings were evaluated to elucidate further such factors having role in the recurrence or prognosis in meningiomas. Seventy four cases of meningiomas were selected to review clinical prognosis and histopathologic findings. The speciemens were re-evaluated with flow cytometry to get DNA histogram. DNA fractions and proliferation index(PI) were calculated. The correlations were statistically analyzed with t-test and ANOVA test. Benign meningiomas were 53(71.6%), atypical 19(25.7%), and malignant 2(2.7%). PI of benign was 10.80+/-1.36 and that of atypical being 18.00+/-5.19. Diploid cases were 48 in number(64.9%) and aneuploid 26(35.1%). PI of diploid was 8.10+/-5.56 and that of aneuploid 24.06+/-18.51. DNA index was 1.00+/-0.00 in enign, 1.00+/-0.33 in atypical, and 1.50+/-0.71 in malignant. There was one case(2%) in benign, 2(11%) in atypical, and 2(100%) in malignant meningioma which showed recurrence(p=0.0002). In benign meningioma, 1 out of 4 subtotally removed cases recurred whereas atypical and malignant meningiomas recurred even in totally removed cases. In conclusion, histopathologically malignant meningiomas have not been always aneuploid. If total removal is done in benign tumor, long-term follow-up is not needed because of no recurrence and no aggravation of symptom. Atypical meningioma with aneuploid and high PI(above 24) should be followed in longer duration, and malignant meningioma should be closely observed due to their higher recurrence rate.