The aim is to substantiate morphologically the resection boundaries of the salivary gland tissue in the surgical treatment of patients with pleomorphic adenoma of different histological variants. Materials and methods: The study used autopsy, surgical and biopsy material, divided into 2 groups. Group 1 included autopsy material (n=6), represented by tissue fragments of the parotid salivary gland, in which macroscopic and microscopic examination did not reveal any general pathological processes. Group 2 included surgical and biopsy material from 30 patients, represented by pleomorphic adenomas with adjacent tissue of the salivary gland at a distance of 0.5 cm and 1.0 cm. Histological, morphometric and statistical research methods were used. Results: The morphological features of the salivary gland tissue which was adjacent to the pleomorphic adenoma at a distance of 1.0 cm, practically corresponded to the physiological norm. However, the tissue of the salivary gland, bordering the tumor at a distance of 0.5 cm, was characterized by pronounced changes. These changes were: violation of the ratio of the specific volumes of the parenchyma and stroma; atrophy of the terminal sections and ducts with cystic expansion of some ducts; thickening of the secretion and formation of calculi in the lumen of some ducts; atrophic and alterative changes in the epithelial lining the terminal sections and ducts; sclerosis and lipomatosis, areas with hyalinosis and dystrophic calcification in the stroma; hemodynamic disturbances in the stroma with a decrease in the number of vessels; pronounced focal or diffuse immune infiltration in the stroma in some areas with the lymphoid follicles formation. Conclusion: The comprehensive study has confirmed that removal of the tumor with the adjacent tissue of the salivary gland at a distance of 1.0 cm in patients with pleomorphic adenoma of various histological variants is the most justified from the morphological point of view.

Currently, titanium plates and screws are widely used to fix bone fragments in maxillofacial surgery. The need for a second operation to remove the metal structure increases the patient's incapacity for work, the economic costs of treatment and the psychoemotional load on the patient associated with anxiety and additional stress. All this has led to the emergence of an alternative method of osteosynthesis using biodegradable plates and screws, which do not have these disadvantages. With all the positive properties of titanium fixators in recent years there has been a large number of publications on the increase in complications after metal osteosynthesis (MOS) using titanium bone plates and screws, which is from 5 to 18 %, therefore, there is a need to remove them after consolidation of bone fragments. The results of the study were the basis for finding ways to obtain the material without metal defect, from which it would be possible to make fixator in the form of plates and screws for the osteosynthesis in maxillofacial region. It was developed biodegradable material of bioactive action (EPU-GAP-LEV) based on polyurethane composition which contains 20 % hydroxyapatite, and 6 % levamisole for osteosynthesis fixator. It was proved effectiveness of EPU-GAP-LEV fixators for osteosynthesis in the treatment of the patients with fractures and deformations of facial skull. Positive results of own clinical researches in early and long terms testified to efficiency and perspective of use of polymeric (including EPU-GAP-LEV) miniplasts in surgical treatment of fractures of facial skull with shift.

The aim is to reveal the expression features of MCA to human papilloma virus type 16 and anti-Epstein-Barr virus in the pleomorphic adenoma, surrounding and intact salivary gland. Materials and methods: It was used surgical and biopsy material from 30 patients, represented by pleomorphic adenomas with surrounding to tumor tissue of the salivary gland and intact tissue of the salivary gland (the distance between the tumor and the intact salivary gland – 10 mm). Immunohistochemical study was performed using mouse monoclonal antibody (MCA) to human papilloma virus type 16 (clone CAMVIR-1, «Diagnostic BioSystems», USA) and anti-Epstein-Barr virus (LMP, clone CS. 1-4, «Dako», Denmark). Visualization was performed, using an EnVisionTM FLEX detection system (Dako, Denmark). Antigen unmasking was carried out in citrate buffer pH 6.0 at 95°C. Primary antibodies were incubated at room temperature for 30 minutes, secondary antibodies – 20 minutes. Sections were counterstained with Gill hematoxylin. We assessed the immunohistochemical reaction by a semi-quantitative method by counting the percentage of positively stained cells in the field of view of a microscope × 400. Microspecimens were studied and photoarchived on an Olympus BX-41 microscope (Japan). Results: In this study it was detected a positive immunohistochemical reaction with MCA to human papilloma virus type 16 and anti-Epstein-Barr virus, respectively, in 26 (86.7%) and 8 (26.7%) cases. Epithelial, mixed and mesenchymal variants of pleomorphic adenoma of the salivary glands are characterized, respectively, by the severely expressed, moderately expressed and minimally expressed of MCA to human papilloma virus type 16 and anti-Epstein-Barr virus. The parenchymal component of pleomorphic adenoma is characterized by more marked expression of these markers as compared to the stromal component. The epithelial cells of the salivary glands, surrounding the pleomorphic adenoma, as well as intact salivary glands, express MCA to human papilloma virus type 16 and anti-Epstein-Barr virus. The severity of the expression of these markers in the salivary gland is determined by the histological variant of the tumor (severely expressed in the epithelial variant, moderately expressed in the mixed variant, and minimally expressed in the mesenchymal variant). Conclusions: The immunohistochemical study has shown that the Epstein-Barr virus and, especially, human papilloma virus type 16 can act as exogenous trigger factors involved in the development of pleomorphic adenoma of the salivary glands. The revealed immunohistochemical features of MCA expression to human papilloma virus type 16 and anti-Epstein-Barr virus in the salivary gland surrounding the pleomorphic adenoma and in the intact tissue of the salivary gland make it possible to recommend the extracapsulardissection of the tumor with resection of the adjacent intact tissue of the salivary gland at a distance of 10 mm in patients with pleomorphic adenoma.

The aim: To describe an integrated approach to the morphological diagnosis of different types of pleomorphic adenomas of the salivary gland. Materials and methods: Surgical and biopsy material from 30 patients with pleomorphic adenomas of epithelial, mixed and mesenchymal variants was studied using histological, immunohistochemical, genetic, morphometric and statistical methods. Results: The results of research allowed us to identify methods for determination the pleomorphic adenomas types. The first method requires an immunohistochemical reaction with a monoclonal antibody to human papillomavirus type 16, followed by counting the percentage of positively stained cells in the tumor. Thus, the mesenchymal variant of the tumor is diagnosed when the percentage of positively stained cells is < 40%. In the mixed variant, this indicator is ≥ 40%, but ≤ 70%, and in epithelial variant – > 70%. The second method was based on the multivariate discriminant analysis. Three formulae were derived to determine the tumor types (Fmesenchymal = - 41.03 + 4.96Х1 + 1.11Х2, Fepithelial = - 22.27 + 3.46Х1 + 0.85Х2, Fmixed = - 122.25 + 5.63Х1 + 3.2Х2, here Х1 - number of vessels, Х2 – specific volume of parenchyma). Conclusions: The authors identified several methods for determining the histological variants of pleomorphic adenomas. These methods will improve the morphological diagnosis of pleomorphic adenomas variants in the preoperative and postoperative periods.