The Study of MIB-1 LI and CD 34 As A Marker of Proliferative Activity and Angiogenesis in Different Grades of Meningioma.

Introduction: Meningiomas comprise 24-30% of all tumours occurring in the central nervous system. Conventional morphologic critera as studied in routine Haematoxylin and Eosin stained sections (H & E) may not be accurate in grading and assessing prognosis in small stereotactic biopsy specimens. Thus, arises the need for objective methods for assessing tumour biology. Angiogenesis is a key event in the spread of tumours and denotes a poor prognosis. Intratumoural Microvessel Density (MVD) helps in quantification of angiogenesis.

Aim: To measure the proliferative index by MIB-1 and correlate it with the WHO grading of meningiomas. Also to assess the expression of CD34 in various grades of meningioma and evaluate their angiogenic potential by calculating MVD.

Materials And Methods: Paraffin blocks of 30 surgically resected cases, 10 each of grade I, II and III meningiomas were reviewed. Tumours were graded and subtyped as per WHO criteria. Immunohistochemical staining was done with MIB-1 and CD 34 antibodies. Statistical analysis was performed using Mann - Whitney U test. p-value of < 0.05 was considered significant.

Results: The male to female ratio overall was 1:1. The age of the patients ranged from 18-81 years. A 73% of patients had raised intracranial pressure and 18.4% of patients presented with seizures. The mean ± SD MIB-1 LI was 1.14 ± 0.84, 8.94 ± 2.73 and 35.62 ± 4.44 in grade I, II and III tumours respectively which was statistically significant. (p< 0.01). The mean ± SD MVD was 49.67 ± 22.35, 41.37 ± 7.45 and 47.86 ± 10.77 respectively in grade I, II and III tumours (p NS).

Conclusion: MIB-1 LI is an important complementary tool to accurately grade meningothelial tumours and assess tumour biology. Specific cycling endothelial markers along with CD 34 & MVD could be used to assess the prognosis of these tumours.