Comparative morphological study of placentas from women with obesity and normal body weight was performed. Expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFR-1, VEGFR-2, VEGFR-3) was detected by immunohistochemical methods. Nonbranching angiogenesis predominated in the placentas from obese women. Immunohistochemical analysis showed reduced intensity of the reaction to VEGF in the syncytiotrophoblast and vascular endothelium of stem villi and enhanced VEGF expression in non-villous cytotrophoblast and endothelial cells of capillaries of mature intermediate and terminal villi; reduced expression of VEGFR-1 and increased levels of VEGFR-2 and VEGFR-3 in the studied structures were also noted.

Comparative morphological study of the placentas in women with preeclampsia and small-for-date fetuses was carried out. Expression of insulin-like growth factor-1 (IGF-1), insulin-like growth factor-2 (IGF-2), and insulin-like growth factor binding protein-3 (IGFBP-3) was detected by immunohistochemical methods. Low expression of IGF-1 and high expression of IGF-2 and IGFBP-3 in the placental tissue depending on preeclampsia severity were detected. The most pronounced changes were found in preeclampsia associated with small-for-date fetuses.

The expression of growth factors and proliferation of endotheliocytes in vascular malformations were studied by immunohistochemical methods. The detected specific features of growth factor expression in the endothelium of venous and arteriovenous malformations seem to reflect the differences in the pathogenesis of these formations. High proliferative activity of the endothelium in angiodysplasias of both types can underlie the disease relapsing.

We conducted a comparative morphological study of placentas from women with gestational diabetes and diabetes mellitus. Morphometry of histological preparations revealed similar type of changes in the studied parameters of placental villi in diabetes mellitus and gestational diabetes. The maximum deviation of the studied parameters from the control was noted in type 1 diabetes mellitus.

Disturbances in the expression of cell adhesion molecules in solid-pseudopapillary tumor cells were detected by immunohistochemical methods. Positive reaction to E-cadherin, catenins, and overexpression of cyclin D1 were found; these changes reflect peculiarities of morphological structure and biological behavior of the studied neoplasms.