Microvessel quantification in benign and malignant ovarian tumors

Microvessel density (MVD) in 92 paraffin sections of ovarian samples of different histologic subtypes was correlated with microvessel counts from 58 corresponding frozen sections. Anti-human von Willebrand factor antibody was used as an endothelial marker. MVD was performed in neovascular hotspots using a Quantimet 500+ Image Analyzer. The highest vessel density (HVD) and average vessel density (AVD) of three fields at the x 200 and x 400 magnification were recorded. There was a strong correlation between the HVD and AVD at the x 200 and x 400 magnifications when comparing fixed with frozen sections (correlation coefficients at x 200 for the HVD was 0.37, P = 0.005 and AVD was 0.30, P = 0.02; correlation coefficients at x 400 for the HVD was 0.38, P = 0.003 and AVD was 0.37, P = 0.004). In the fixed tissue, the HVD and AVD at both these magnifications were significantly greater in the group containing functional cysts; this was also the case for the frozen sections. These findings are consistent with the development of a microcirculation necessary for the growth and maturation of such cysts, and this appears to be greater than that in tumors. The good correlation between MVD in fixed and frozen sections suggests that such observations represent a true reflection of ovarian angiogenesis in both physiologic and pathologic states.