Background: The aim of the present study was to evaluate microvessel density (MVD) in the cellular layers of ovarian endometriomata, with particular interest in the relationship with VEGF and survivin expressions by endothelial cells and with the diameter of the cysts.
Materials and methods: MVD and VEGF and survivin endothelial cell expressions were evaluated in 26 ovarian endometriotic cysts and correlated with the cyst diameter.
Results: The mean MVD was higher in the inner specialized stroma of ectopic endometrium than in the outer fibrous capsule, but only in the fibrous capsule was MVD correlated with endothelial cell VEGF and survivin expressions as well as with the cyst diameter.
Conclusion: The diameter of ovarian endometriotic cysts seems to be related to the angiogenic process involving the outer fibrous capsule, and not the inner specialized stroma of ectopic endometrium, since only in the capsule are vessels stimulated to proliferate by VEGF and protected from apoptosis by survivin, and their density is correlated to cyst diameter.