Morphofunctional and immunohistochemical characteristics of the large omentum in ovarian cancer

Abstract

The aim of the study was to establish morphofunctional and immunohistochemical characteristics of large omentum in women with ovarian cancer.Material and methods. The large omenta of 48 women with ovarian cancer (low-grade differentiated seropapillary adenocarcinoma of high-grade malignancy) of II stage (n=20) and III stage (n=28) were studied. Histological sections were stained with overview histological and immunohistochemical methods (to reveal ki67, P53, CD34, CD7, CD4, CD8, CD61 proteins expression). Results. In patients, the size of the large omentum was characterized by high individual variability; in the presence of metastasis, the size of the omentum was reduced. Intensive development of blood vessels in the organ was noted, but in the presence of metastases stasis of blood corpuscles, leucocytic infiltration, and moderate edema of connective tissue were observed in the organ’s vessels. Areas of lymphoid tissue, both small lymphatic follicles and diffusely located lymphoid tissue, were revealed in the omentum. In most follicles, reactive centers were not marked, and the number of follicles was reduced in the presence of metastases in the omentum. The analysis of CD34+ cells distribution showed that they were identified both in the tumor and in the areas of the omentum adjacent to the tumor, which indicates a pronounced angiogenesis. An irregular distribution of CD7+ and CD8+ and CD4+ cells was revealed in the tumor tissues, as well as in the surroundings. Simultaneously with the expression of P53 protein, ki67 protein expression is revealed in the significant number of tumor cells (including endothelial cells of tumor blood vessels). The proportion of ki67+ cells in the tumor cell population was 60.1±3.3%. The presence of a large number of ki67+cells in the presence of P53 protein expression in them indicates the aggressiveness of the tumor, as well as a disturbance of apoptosis regulatory mechanisms in the cells. Ki67 expression was low in the omentum areas unaffected by metastases, and it was revealed in the certain areas of connective tissue in fibroblastic programmed differentiation cells. Conclusion. The results obtained indicate significant plasticity and reactivity of great omentum in the presence of tumor process in the body and confirm the important role of great omentum in protective reactions.