Morphometric study of nuclei and microvessels in gliomas and its correlation with grades.

Introduction: Modifications of nuclear morphology in conjunction with alteration in microvascular configuration are essential features encountered during the progression of glial tumors. In order to gain more insight into tumor biology of gliomas, objectives of the study were selected (a) to correlate morphometrically evaluated nuclear parameters [nuclear area (NA), nuclear perimeter (NP), nuclear density (ND), percentage of total nuclear area (%TNA)] and microvessel parameters [microvessel density (MVD), microvessel caliber (VC), microvessel cross sectional area (VCSA), total microvessel boundary density (TVBD), percentage of total VCSA (%TVCSA)] with WHO grading; (b) extend such correlations to the ratio parameters: ratio of MVD to ND (MDV/ND), ratio of TVBD to %TNA (TVBD/%TNA) and ratio of %TVCSA to %TNA (%TVCSA/%TNA); and (c) to correlate microvessel and ratio parameters with NP and ND.

Materials And Methods: A total of thirty gliomas managed at this institute during 2009-2012 were evaluated for various nuclear and microvessel parameters by image morphometry using a computerized digital photomicrograph system. For assessment of microvessel parameters CD34-immunostained sections were used while nuclear morphometry was performed on routine hematoxylin-eosin-stained sections. Appropriate statistical analysis was performed in correlation studies.

Results: All nuclear morphometric parameters showed strong positive correlation with tumor grades (r>0.7). In contrast, though all microvessel parameters exhibited positive correlation with grades, the parameters TVBD and %TVCSA showed strong positive correlation. The ratio parameters (MVD/ND) and (TVBD/%TNA) showed negative correlation with grades, whereas (%TVCSA/%TNA) did not exhibit meaningful correlation with grades. Further, while all microvessel parameters showed positive correlation with NP and ND; ratio parameters showed negative correlation with them.

Conclusion: This study indicates that the parameters related to tumor growth (NA, NP, ND, %TNA), and angiogenesis showed increasing trend with tumor grades simultaneously; whereas the parameters related to supply of nutrients per nucleus showed decreasing trends with tumor grades, nuclear size and nuclear density. Thus, the former accounts for increased cellularity, mitosis, and vascular proliferation, while the latter culminates in tumor necrosis, all of which are essential components for grading of gliomas. The present study will therefore have a vital role as surrogate markers of grading of tumor.