Solitary Fibrous Tumor of the Great Omentum: A Case Report and Literature Review

Background: We report a case of a 23-year-old man with a solitary fibrous tumor of the great omentum who presented clinically as a case of dull abdominal pain. Case Presentation: Solitary fibrous tumor normally occurs in the visceral pleura. Extrathoracic solitary fibrous tumor is rare, especially those from the great omentum, with approximately 31 cases reported in the literature. Conclusion: After reviewing and summarizing the imaging findings of 31 cases of solitary fibrous tumor of the greater omentum, we considered that the characteristic findings can provide a reliable basis for preoperative diagnosis.

Morphofunctional and immunohistochemical characteristics of the large omentum in ovarian cancer

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.

Morphological changes of a great omentum at implantation of polypropylene and composite prostheses at allohernioplasty

To date, allohernioplasty of giant postoperative ventral hernias retains high postoperative mortality and a significant number of postoperative complications. The purpose of the study is to investigate the possibility of intraperitoneal use of polypropylene and composite implants in allohernioplasty of postoperative giant ventral hernias by studying the morphological changes of the great omentum. The results of surgical treatment of 146 patients with postoperative giant ventral hernias were investigated. To this group of patients with allohernioplasty by the method onlay was performed 22 (15.1%) patients, by the method sublay – 46 (31.5%), by the method inlay – 52 (35.6%), with intra-abdominal placement of the mesh by the method onlay (intraperitoneal onlay mesh) – 26 (17.8%). 32 (21.9%) patients who underwent surgery using the sublay method polypropylene implant was fenced off from the abdominal organs with a great omentum, 22 (15.1%) patients operated on by the intraperitoneal onlay mesh method composite implant was also fenced off from the abdominal organs by a great omentum. In 8 (5.5%) patients from the group of patients who were operated on by the sublay method and in 6 (4.1%) – operated by the intraperitoneal onlay mesh method for 14-18 days patients developed signs of chronic intestinal obstruction, where the cause was postoperative adhesive illness. The study of the effect of polypropylene prosthesis on a great omentum was performed on 8 outbred dogs and 6 outbred mature dogs, who were implanted with a composite mesh unilaterally covered with oxycellulose. The polypropylene implant has been shown to have a greater capacity for the development of adhesive processes. However, if a great omentum to protect this prosthesis from the abdominal cavity then the first zone (active inflammation) spread in 155 microns (increase in the number of blood capillaries of the microcirculatory bed, thickening of the arterioles wall, venous full blood flow, diapedesis of leukocytes through the wall of the blood cells), the second zone (sclerosis) – up to 40 microns (increase in the number of macrophages and lymphocytes. proliferation of fibroblasts). In the future, the structure of the omentum was almost indistinguishable, so with allohernioplasty by the developed method, it was possible to prevent the development of adhesive disease on the intestine. This study confirmed the limited spread of the inflammatory response, which allows the implant of a polypropylene mesh on a great omentum. In the composite mesh, the composite mesh was spliced with surrounding tissues from the side where there was no gel coating, and from the side of the salivary coating, the “readiness” to spread the inflammatory process (vasculitis with pronounced lympho-plasmocytic infiltration of the vessel walls and perivascular ductus), therefore, left it is also necessary to enclose it with a large omentum from intestium.

Influence of omentoplasty on colonic anastomosis in animals submitted to hemorrhagic shock in rats

PURPOSE: To analyze influence of omentoplasty on anastomosis in descending colon of rats. Rats were submitted to the hypovolemic shock of the hemorrhagic type by the Biomechanical Test of Pressure of Rupture by Liquid Distension (BTPRLD). In addition, establish a type of acute anemia in rats that are provided to the study. METHODS: Comparative study between two groups of animals with ten rats in each one, all submitted to hemorrhagic shock for 30% volemic removal by the carotid artery. An anastomosis was performed in left colon. An anastomosis was performed in the left colon. Group 1 took place anastomosis with Polyvinyl Chloride (P.V.C) film to prevent the adhesions formation on sature line. Group 2 placed the great omentum around the anastomosis. Euthanasia occurred on the fifth day, when the anastomoses were submitted to the biomechanical test of pressure of rupture by liquid distension (BTPRLD). RESULTS: High rupture pressure was gained with omentoplasty group in relation to the group in which anastomosis was protected from adhesions formation. A statistical significance was noted. CONCLUSION: Protection by great omentum has increased the anastomosis resistance of the shocked animals. Also, the proposed hemorrhagic shock type has proven to be useful for this study.