Résumé
Background: Astrocytomas are common malignant brain tumours. Ki-67/MIB-1 index serves as an important supplementary tool in the diagnosis and prognosis of human astrocytoma
Methods: Forty [40] cases of various histopathological [WHO] grades of astrocytoma [Pilocytic, diffuse, Anaplastic and Glioblastoma multiforme] were included in this study. Ki-67/MIB-1 labelling index of these tumours was estimated by immunohistochemistry, performed on paraffin sections. Histopathological grading and Ki-67/MIB-1 labelling index were compared. The results were analyzed by one way ANOVA
Results: Out of 40 cases two were diagnosed as pilocytic astrocytoma [WHO grade-1] with a mean Ki-67/MIB-1 labelling index of 0.7+/-1.4 [range 0.6-0.8%]. Thirteen cases were of diffuse astrocytoma [WHO grade II], with a mean Ki-67/MIB-1 labelling index of 3.07+/-3.7 [range 1-15%]. Nine cases were diagnosed as Anaplastic astrocytoma [WHO grade III] with a mean Ki67/MIB-1 labelling Index of 11.55+/-7.8 [range 2-35%]. Sixteen cases were diagnosed as Glioblastoma multiforme with a mean Ki-67/MIB-1 labelling Index of 14.1+/-8.9 [range [5-36%]. ANOVA showed a significant differences between four compared groups [p=0.003]
Conclusion: Immunohistochemical analysis of Ki-67/MIB-1 labelling index increases significantly with increasing grade of malignancy. The Ki-67/MIB-1 labelling index can be used as an adjuvant to histopathological grading for proper diagnosis and grading of astrocytoma especially in borderline cases and in small biopsies