Objective. The aim of this study was to evaluate the quantification of angiogenesis by assessing microvessel density in cervical cancer, comparing the performance of three monoclonal antibodies: anti-CD34 and BNH9, which are still little known markers in cervical neoplasia, and anti-CD31. Methods. Fifty-four consecutive patients diagnosed with stages I and 11 invasive cervical cancer undergoing radical hysterectomy and bilateral pelvic lymphadenectomy were evaluated. The monoclonal primary antibodies used were anti-CD34, anti-CD31 and BNH9 antibody. The areas of highest microvessel density were used for counting microvessels in 10 high-power fields. Microvessel density was the mean vessel number counted in 10 high-power fields. Results. The mean of microvessel density was 10.3, 9.7 and 5.8 for anti-CD34, BNH9 and anti-CD3 1, respectively. According to the Kruskal-Wallis nonparametric test, microvessel density estimated by anti-CD34 and BNH9 was significantly higher than the microvessel density estimated by anti-CD31. The difference between microvessel density measured by anti-CD34 and BNH9 was not statistically significant. There was diagnostic agreement in 44 out of 54 cases for anti-CD34 and BNH9 monoclonal antibodies, kappa coefficient being 0.63. The kappa coefficient was 0.41 between anti-CD34 and anti-CD31 and 0.26 between anti-CD31 and BNH9. Conclusion. The anti-CD34 and BNF19 seem to have higher sensitivity than anti-CD3]. The agreement to quantify microvessel density between anti-CD34 and BNH9 is higher than between them and anti-CD31. Additionally, considering that the BNH9 is much less unknown than anti-CD34 and that they showed very similar performance, the BNH9 clinical significance should be test in different neoplasms. (C) 2004 Elsevier Inc. All rights reserved.931121124