Background:The most common malignant tumors of the uterus are endometrioid adenocarcinomas (EA). Their prognosis depends on the qualitative characteristics of the neoplastic cells and their stroma. The neovascularization of EA tissues and level of microvascular density (MVD) influence tumor progression. Our study aims to establish the relationship between MVD in EA tissue and the histological and immunohistochemical features of tumors.Materials and methods:The authors studied 30 cases of endometrial ЕА and compared their histological and immunohistochemical characteristics with the MVD of tumor tissues.Results:Our study indicated that MVD in EA tissue depends on the grade of the tumors and their FIGO stage. Increased MVD was correlated with a depression of E-cadherin and PR expression and enhanced expression of VEGF and Ki-67. MVD enhancement during VEGF overexpression is a manifestation of the functional activity of these proteins. The increase in MVD was accompanied by more frequent metastasis of the EA to the lymph nodes.Conclusion:EA progression is accompanied by qualitative and quantitative variations of parenchymal and stromal patterns of tumors. Dedifferentiation of EA leads to overexpression of VEGF, which becomes diffuse in tumors cells, resulting in an increase of adenocarcinomas’ MVD and their metastatic potential. Correlations between histological and immunohistochemical features of EAs indicate the synchronicity of the occurrence and progression of morphological and immunological anaplasia, which can be used in predicting the course of the disease.