Comparison of Proliferative Activity in Each Histological Subtypes of Benign and Atypical Intracranial Meningiomas by PCNA and Ki-67 Immunolabeling = 양성 뇌수막종의 조직학적 아형 및 이형성 뇌수막종에서 PCNA와 Ki-67 표지지수의 비교

다국어 초록 (Multilingual Abstract)

Objective : The clinical prognosis and biological behavior of atypical and especially malignant meningiomas are well known to be worse than benign meningioma, but the degree of biological aggressiveness in each classical subtypes of benign meningioma is controversy. This study was performed to see whether there is a difference in the proliferative activity between each different histological subtypes of benign meningioma as well as atypical meningioma. Methods : Paraffin-embedded surgical specimens of 27 meningiomas, including two recurrent tumors, were studied to evaluate proliferative activity by immunohistochemical method with monoclonal antibodies to proliferating cell nuclear antigen(PCNA) and MIB-1. The specimens consisted of 8 cases of meningothelial, 9 cases of transitional, 5 cases of fibroblastic subtypes and 5 cases of atypical meningiomas. Results : Mean PCNA labeling indices of meningothelial, transitional and fibroblastic meningiomas were $4.82{\pm}5.10%$, $9.01{\pm}4.25%$ and $5.66{\pm}5.32%$, but that of atypical meningiomas was $27.62{\pm}19.67%$, noting a higher value compared to all three subtypes of benign meningiomas. Mean Ki-67 labeling indices of the above 3 subtypes were $0.43{\pm}0.85%$, $0.44{\pm}1.08%$ and $0.24{\pm}0.18%$, and that of atypical meningiomas was also revealed to be of higher value ($0.84{\pm}0.59%$). PCNA and Ki-67 labeling indices were not statistically different between histological subtypes of benign meningioma(p>0.05), but the differences of both immunolabeling between benign and atypical meningiomas were statistically significant(p<0.05). Conclusion : Immunolabeling of PCNA and Ki-67 in intracranial meningiomas reveals no prognostic difference between meningothelial, transitional and fibroblastic subtypes in classical benign meningiomas by measuring expression of PCNA and Ki-67, but it seems to be helpful in differentiating benign and atypical meningioma, later showing more proliferative activity and biological aggressiveness.