Introduction Endometriosis ranks second place in the structure of infertility. The development of endometrial dysfunction is one of the infertility factors, which affects the degree of decrease in the receptive abilities of endometrium and subsequent implantation.

Purpose of the study was to reveal morpho-functional state of receptivity and nidation ability of endometrium in patients of reproductive age with diffuse and nodal forms of adenomyosis.

Materials and methods The study included 104 patients, which were divided into 2 groups. The first group consisted of 30 patients with a diffuse form of adenomyosis, second group included 30 patients with a nodal form. The patients underwent aspiration biopsy of endometrium in the middle secretory phase. The level of ER and PR expression in the glandular and stromal compartments of endometrium was assessed, the percentage and degree of maturity of pinopodes were determined.

Results The analysis of ER and PR number in the stromal and glandular components of endometrium in patients with diffuse adenomyosis revealed an increase in the secretion of ER in the glandular cells in contrast to patients of the comparison group. Significant differences in the expression of ER and PR in glandular cells were verified among observed with the nodal form of adenomyosis. The immunohistochemical reaction with antibodies to ER and PR in the nodal form of adenomyosis was significantly higher than in diffuse form. Both in the first and second groups, a decrease in the formation ability of pinopodes on the superficial epithelium was noted.

Discussion Adenomyosis leads to damage of the morpho-functional state and receptive abilities of the endometrium. In the nodal form the degree of detected disorders was significantly higher.

Conclusion The nodal form of adenomyosis is more common in patients of younger reproductive age and is associated with a higher prevalence of endometrial dysfunction. This is especially important for the selection of adequate modern therapy in order to maintain and improve reproductive function.

Introduction One of the criteria of impaired DNA repair is microsatellite instability (MSI) resulting from functional insufficiency of the mismatched nucleotide repair (MMR) system, a complex of proteins (MLH-1, PMS- 2, MSH-2, MSH-6). No data on the study of MSI in chronic endometritis (CE) were found in the available literature.

The aim of the study was to determine the structural features of microsatellite instability in the endometrium in female patients with chronic inflammation of the uterine mucosa.

Materials and methods Group I consisted of 30 women with morphologically confirmed high-grade CE; Group II consisted of 30 patients with low-grade CE; Group III consisted of 30 women who sought pregnancy planning and had histologically unchanged endometrium. The degree of CE in patients in groups I and II was variable. We analyzed the expression levels of MLH-1-, MSH- 2-, MSH-6-, and PMS-2-proteins in the endometrium by estimating the staining area of nuclei and cytoplasm of the affected cells over the entire slice area. Nonparametric statistical methods with Mann-Whitney test were used. The value of probability of error was set at 0.05.

Results There was a statistically significant decrease in the level of MMR protein expression in the endometrial samples from the Group I patients compared to the same indices in the Group II and III women. No statistically significant results were found when analyzing the level of MMR protein expression depending on the severity degree of CE.

Discussion There was a statistically significant decrease in the expression level of the markers studied (MLH-1, PMS-2, MSH-2, MSH-6) in endometrial specimens from patients with low-activity CE compared to uterine mucosa biopsy specimens from highly active CE and mid-stage endometrial secretion phase specimens. The described morphological features of the uterine mucosa in patients with low-activity CE are consistent with the findings of other authors. The literature provides indications of structural features of MSI in pre-tumor and tumor processes in the uterine mucosa.

Conclusion Endometrial samples with low activity and various degrees of CE show statistically significantly lower expression levels of MLH-1, PMS-2, MSH-2, MSH-6 when compared to biopsy specimens from highly active CE and normal endometrial samples, which may indicate pathogenetic heterogeneity in the development of inflammation in the endometrium.

Introduction No data on experimentally substantiated parameters and modes of diode laser radiation allowing a minimally traumatic surgical treatment of intrauterine pathology have been found in the literature.

The aim of the investigation was to substantiate experimentally the optimum parameters and modes of diode laser radiation in the treatment of intrauterine pathology based on the study of morphological changes in the endometrium.

Materials and methods 48 endometrial samples were exposed to 10-40 W diode laser power in a constant mode and 15 samples - in a pulsed mode with 3 different sets of laser exposure parameters. The data were statistically processed using Microsoft Excel spreadsheets, version 16.49. The differences were considered statistically significant at р<0.05.

Results Width of the ablation zone, lateral coagulation and hyperthermic exposure zone was calculated at the most optimal parameters of laser energy (20 W), achieving adequate cutting and bleeding properties of the laser. The most effective in the pulsed mode of laser operation was 30 W amplitude power of radiation, the pulse duration of 100 ms, the duration of the interval between pulses of 50 ms, the average power of 20 W.

Discussion Comparative analysis of morphometric parameters in the action of laser radiation in the constant mode with a radiation power of 20 W and in the pulsed mode with an average laser power of 20 W has shown that the structural parameters have significantly lower values in the pulsed laser mode.

Conclusion Optimal cutting properties of the laser are observed when constant laser irradiation with a power of 20 W is used. The best cutting and bleeding properties were demonstrated by the pulsed laser mode with an average power of 20 W, amplitude power of 30 W, pulse duration of 100 ms, and inter-pulse interval of 50 ms.

Introduction Cirrhosis of the liver is one of the leading problems of modern medicine in Russia and the world, the incidence of which tends to increase at the present time, and mortality among liver diseases with cirrhosis reaches 47%.

The purpose of the work is to evaluate the significance of metalloproteinases (MMPs) and their inhibitors in the formation of liver fibrosis and cirrhosis in the outcome of chronic hepatosis of mixed toxic etiology and the use of OD in the experiment.

Materials and methods In Wistar rats of group 1, posttoxic chronic hepatosis was induced by injections of 50% CCl4 oil solution intraperitoneally and 6.5% aqueous solution of ethyl alcohol per os for 60 days. Animals of the 2nd (experimental) group – against the background of the injections of toxic factors from the 30th day of the experiment, for the next 60 days intraperitoneally injected 2 ml of 5% aqueous solution of oxidized dextran (Mr 40 kDa). The numerical density of Kupfer cells, expressing MMP-2, MMP-9, TIMP-1 was studied in the liver.

Results From the 60th day, group 1 rats developed cirrhosis of the liver with the formation of false lobules. With the injections of oxidized dextran, the number of Kupfer cells expressing MMP-2, MMP-9 was up to 2 times less than in group 1 rats. The numerical density of Kupfer cells expressing TIMP-1 in group 2 rats was 3 times higher on day 60 than in group 1 rats. In group 2 rats, by the 90th day, a decrease in the number of Kupfer cells expressing MMP-2, MMP-9 by 2 times, and TIMP-1 by 3 times was observed.

Discussion OD in chronic toxic hepatosis has an antifibrotic effect that prevents the formation of liver cirrhosis, due to both the processes of collagen degradation in the extracellular matrix under the influence of MMP-2, MMP-9, and associated with a violation of the collagen assembly process, apparently due to the “blockade of the assembly” of tropocollagens by aldehyde-aldehyde bond with oxidized dextran.

Conclusion The use of OD in chronic toxic hepatosis prevents the formation of liver cirrhosis in the experiment due to increased processes of collagen degradation in the extracellular matrix under the influence of MMP-2, MMP-9.

Introduction Diagnosis of the gastric mucosa atrophy represents an important problem, the solution of which depends on the possibility of secondary prevention of gastric cancer. A possible way of solution is the use of immunohistochemical markers - proteins associated with cellular remodeling of gastric mucosa, PDCD4 and CDX2.

The aim of the work is to evaluate the possibility of using immunohistochemical markers PDCD4 and CDX-2 to diagnose atrophy of the gastric mucosa in chronic gastritis and increase the informative value of biopsy examination.

Materials and method The object of the study was 155 cases of biopsy examination of the gastric mucosa of patients with chronic gastritis (5 fragments per case − 775 biopsy specimens). A comparative semi-quantitative assessment of immunohistochemical expression of CDX2, PDCD4 at different stages of chronic gastritis was performed. Spearman correlation coefficient was used to assess correlation relationship.

Results There were no statistically significant differences in the level of PDCD4 in studied samples depending on the stage of chronic gastritis, p=0.06. Statistically significant increase of CDX2sum index in progressing stage of chronic atrophic gastritis (p=0.005), demonstrated a pronounced positive correlation r=0.70 (p<0.01).

Discussion According to the results obtained, it is shown that the decline in PDCD4 protein does not occur with the progression of atrophy severity. Complementary use of immunohistochemical marker CDX2 is able to give an idea of the presence and severity of both metaplastic and absolute atrophic changes in the gastric mucosa.

Conclusion Equally high level of PDCD4 protein index in the gastric mucosa at different stages of chronic gastritis excludes the possibility of its use as an immunohistochemical marker of atrophy. Semi-quantitative immunohistochemical index of CDX2 protein can be used as an additional marker in decision support system for assessment of atrophic changes in gastric mucosa. 

Introduction The Cdx2 gene provides an intestinal differentiation of epithelial cells and plays an oncosupressive role. An indirect method of the Cdx2 gene expression assessment is the immunohistochemical study of its product, the CDX2 protein. Therefore, the common approach to the immunohistochemical study of the CDX2 protein hasn’t been developed yet. A semi-quantitative CDX2 index based on the percentage of CDX2-positive cells in the tissue specimen, the staining intensity and an expression pattern has been proposed.

The purpose of the study was to assess the reproducibility of the semi-quantitative CDX2 index calculation in chronic atrophic gastritis stages I-IV.

Materials and methods 20 chronic atrophic gastritis cases (5 cases for each stage of the gastritis according to the Operative link for gastritis assessment system) were taken according to the Maastricht V protocol and examined by the immunohistochemical method (CDX2, clone EPR2764Y, ready to use). The reproducibility of the CDX2 semi-quantitative index was assessed by five pathologists. An agreement between observed raters was measured by the kappa statistics.

Results The Cohen’s κ value is 0,8 for unweighted κ and 0,97 for weighted κ (extremely high level of agreement) for the semi-quantitative CDX2 index calculation.

Discussion The least reproducible parameter used for the semi-quantitative CDX2 index calculation the percentage of CDX2-positive cells because of the subjective assessment. The Cohen’s weighted κ value was higher compared to the unweighted κ because of the close yet not similar CDX2 semi-quantitative index values calculated by pathologists.

Conclusion The semi-quantitative CDX2 index can be used to rank CDX2 expression and has a high level of reproducibility. 

Introduction Uveal melanoma (UM) is a malignant neoplasm of the vascular tract of the eye, prone to hematogenous metastasis, regardless of the type of treatment performed. Prediction and probability of UM metastasis is one of the main tasks of onco-ophthalmology. We decribed an alternative method of tumor blood supply due to the process of vasculo-like mimicry (VM) with the formation of pseudovascular structures of tumor cells is described. At the same time, the participation of the microenvironment in the processes of VM and metastasis is currently debatable and relevant.

Purpose of the work was to evaluate the prognostic role of macrophage vasculiform mimicry in the progression of chorioid melanoma based on the histological and immunohistochemical characteristics of surgical material.

Materials and methods The surgical material of choroidal melanoma after enucleation for the period 2013-2018 was studied. Histological, histochemical (PAS reaction) and immunohistochemical studies were carried out using markers CD68 (macrophages), CD 34, CD31, D2-40 for the purpose of qualitative and quantitative assessment of macrophages in the stroma of tumors, large vessels and pseudovessels in the tumor.

Results The ability of macrophages to form vasculo-like spaces in choroidal melanoma has been discovered and described. In growth with macrometastases, more phage representatives are recorded than in tissue samples of non-metastasizing melanoma. the volume of the macroscopic mass of the ulcer and the growth rate of phages were registered as the inverse average in terms of the strength of the correlation. In group studies with metastases, an increase in the volume of pseudovascular volumes and the number of phages is recorded.

Discussion The macrophage microenvironment in a tumor can play a dual role: antitumor and protumor. The ability of macrophages for VM in UM has been described. The results of our macrostudy confirm the protumor activity of phages and their important role in tumor metastasis.

Conclusion In-depth study of the ways of pseudovascular space formation not only by the cells of the tumor itself, but also by its microenvironment, helps to open new directions in the study of predictors of UM metastasis and outline approaches to the development of new directions of anti-tumortherapy.

Introduction Singling out such diagnostic category as atypical small acinar proliferation of the prostate (ASAP) determines the necessity of forming additional approaches to differential morphological diagnosis in order to determine adenocarcinoma in time. Cell renewal index (CRI) is actively used to study proliferation and apoptosis in the epithelial cells of hormone-dependent glands, but in prostate pathology this criterion has not been studied.

The aim of the study was to characterize the cell renewal index in atypical small acinar proliferation and prostate adenocarcinoma of different degrees of differentiation in order to optimize differential diagnosis.

Materials and methods We studied 720 prostate biopsy specimens from 60 patients: Group 1 — 15 patients with ASAP; Group 2 − 15 with adenocarcinoma of high-grade of differentiation; Group 3 − 15 with moderately differentiated adenocarcinoma; Group 4 − 15 with low differentiated adenocarcinoma. We used immunohistochemical method (Ki-67, CPP32) and non-parametric statistical methods of investigation.

Results The CRI in ASAP was comparable to that in highly differentiated adenocarcinoma (p=0.5). In moderately differentiated adenocarcinoma the CRI was significantly higher than in ASAP and highly differentiated adenocarcinoma (p=0.004). The greatest increase in CRI was noted in the low-differentiated adenocarcinoma group, which was higher and significantly different from the ASAP (p=0.000), highly differentiated carcinoma (p=0.003) and moderately differentiated prostatic carcinoma (p=0.000) groups.

Discussion On the basis of statistical analysis the present study helped to reveal the identity of CRI parameters in ASAP and highly differentiated adenocarcinoma of the prostat, which allows to add a number of morphological criteria for transferring patients from the group of undetermined diagnosis of ASAP to the group of adenocarcinoma. There is a need for further investigation of CRI with multiparametric analysis including investigation of the expression levels of hormones involved in the regulation of cell renewal in the prostate and growth factors associated with them.

Conclusion The study allowed to reveal the identity of the CRI in ASAP and highly differentiated adenocarcinoma of the prostate, which can supplement a number of morphological criteria for transferring patients from the group of undeterminate diagnosis of ASAP to the group of adenocarcinoma.

Introduction This article presents the current views on follicular thyroid tumor of undetermined malignant potential (FTUMP) taking into account the principles of WHO classification. Molecular genetic study with identification of mutation of some genes as well as determination of expression level of some microRNAs are given as methods for detection of potential predictors of oncodiagnostics. It was shown that the state of nucleus organizer regions is a marker of cell proliferation rate.

The aim of the investigation was to estimate prognostic significance of expression level of some microRNAs and amount of regions of the nucleus organizers in the thyroid tissue at FTUMP to objectify approaches to development of adequate surgical tactics.

Materials and methods Profile, microRNA expression level by real time PCR and regions of the nucleus organizers were studied in 98 cases of FTUMP which made up 4.75% of all cases of thyroid tumors operated on during four years.

Results In 29 (29.6%) cases the spectrum of microRNA typical for malignant neoplasms was registered in the tissue of the FTUMP. In the remaining 69 (70.4%) cases out of 98 observations the spectrum and the expression level of microRNA corresponded to the follicular adenoma. Statistically significant differences in the average number of AgNORs and correlation between the cell area and the number of AgNORs granules were found within the formed subgroups.

Discussion Increase of the mean number of AgNORs and the ratio of the nucleus area to the number of silver nitrate granules in the 2nd subgroup in comparison with the 1st one, as well as the appearance of the type II cells testifies to the appearance of the proliferating tumor cells in a new tumor growth and can be considered as prognostic criteria of tumor malignization. These results correlate with the findings of molecular-genetic study.

Conclusion The data of the literature and the results obtained by studying the profile and the expression level of a number of microRNAs, morphometric characteristics and counting of thyrocyte nucleus organizer regions may serve as additional criteria for evaluation of the proliferative activity of the follicular epithelium in thyroid neoplasms, in particular to clarify the malignancy potential. Preoperatively diagnosed conditionally malignant FTUMP will allow to justify the necessity and amount of surgical intervention, and if a complex of criteria of conditionally benign FTUMP is revealed, to stick to the waiting tactics and refuse surgical intervention.

Introduction Clinical and morphological characterization of pituitary adenomas remains a topical problem of great importance in view of lesions in persons of working age.

Purpose of work was to identify clinically relevant morphological and immunohistochemical features of pituitary adenomas.

Material and Methods Sixty-two adenomas were studied: 25 in men and 37 in women. Pituitary adenoma was most frequently diagnosed between 51 and 70 years of age. Adenomas were mostly of small and medium size with predominance of supra- and laterosellar location. There were 41 hormone-positive adenomas and 21 “dumb” neoplasms without signs of trophic hormone synthesis. Gonadotropinomas and corticotropinomas prevailed among hormone-positive adenomas. Ki67 index in our material did not exceed 1−2%, which is a favorable prognostic factor for low recurrence of adenomas.

Results 62 adenomas were studied, 25 in men and 37 in women. Vast majority of adenomas were diagnosed at the age of 51 to 70 years. Adenomas mainly had small and medium size, with a predominance of supra- and laterosellar localization. Out of 62 adenomas 41 were hormone-positive, and 21 were “silent” neoplasms without signs of synthesis of trophic hormones. Among hormone-positive adenomas, most were gonadotropinomas and corticotropinomas. The Ki67 index in our material did not exceed 1-2%, which is a favorable prognostic factor for low recurrence of adenomas.

Discussion In contrast to previously published works, gonadotropinomas and corticotropinomas prevailed in our material. The most diagnostically important markers were identified and applied for routine morphological verification of pituitary adenomas.

Conclusion The predominance of hormone-positive adenomas of small size was a peculiarity of the work. At the same time, hormone-positive tumors had no clinical manifestations for quite a long time and were latent. Low proliferativity of the studied adenomas was a favorable prognostic sign.

Introduction Evaluation of immunohistochemical expression of matrix metalloproteinases 2 and 9 (MMP2, MMP9), their inhibitors (TIMP1, TIMP2), fibroblast growth factor (FGF2), transforming growth factor beta (TGFB1) and collagen type III in the bone marrow of patients with Ph-negative myeloproliferative neoplasms (MPN) is of great importance.

The aim of the study was the evaluation of expression of extracellular matrix components (MMP-2, MMP-9, TIMP1, TIMP-2, FGF2, TFGB1, Collagen III) involved in myelofibrosis progression in bone marrow trepan biopsies depending on mutational status of patients with CMPD.

Materials and methods We analyzed 108 bone marrow biopsies of patients with MPN, which were divided into 3 groups: JAK2-positive (n=62), CARL-positive (n=25) and triple-negative (n=21). Whole-slide sections were immunostained using antibodies against MMP-2, MMP-9, TIMP-1, TIMP-2, FGF2, TGFB1, collagen type III and scored by ImageJ plugin software. We used Kruskal- Wallis test and Mann-Whitney U-test for comparisons of differences in medians. Spearman’s rank order correlation was calculated. Statistical significance was set at p<0,05.

Results and Discussion MMP2 expression was observed in megakaryocytes. MMP9 expression was observed in neutrophils, macrophages and the bone marrow extracellular matrix (EM). TIMP1 expression was observed in the EM. TIMP-2, FGF2, TGFB1 and collagen type III expression was observed in megakaryocytes and the EM. Kruskal-Wallis test determined the differences between all 3 groups (MMP- 2 p< 0,001, MMP-9 p=0,023, TIMP-1 p< 0,001, TIMP-2 p< 0,001, FGF2 p< 0,001, TGFB1 p< 0,001, collagen type III p< 0,001). Mann-Whitney U-test determined the most differences between JAK2- and CALR-groups (MMP-2 p=0,001, MMP-9 p=0,001, TIMP-1 p=0,001, FGF2 p=0,001, TGFB1 p=0,001, collagen type III p=0,001), except TIMP-2. There was the weak and moderate positive correlation between JAK2-mutation and the immunohistochemistry expression of EM components, also the weak negative correlation between CALR-mutation and the immunohistochemistry expression of EM components.

Conclusion The bone marrow immunohistochemistry expression of MMP-2, MMP-9, TIMP-1, TIMP-2, FGF2, TGFB1, collagen type III depends on driver mutations. It may be useful for understanding of fibrosis pathogenesis and prognosis estimate of Ph-negative MPN.

Introduction The literature describes atypical clinical forms of psoriasis and atopic dermatitis in children that combine features of both diseases. In such cases, dermatologists resort to biopsy of plaque skin elements in the complex diagnosis. However, the histological picture in these biopsy specimens is uncertain and does not allow to make an unequivocal judgment about the correspondence of changes to one or another disease.

The purpose of work was to compare pathomorphological changes in biopsy specimens of plaque skin elements in children with undetermined clinical picture of the disease with changes in typical forms of psoriasis and atopic dermatitis.

Materials and methods A morphometric study of 10 plaque skin biopsy specimens from children (mean age 9.2±1.11 years) with an indeterminate clinical picture of the disease was performed. The obtained data were compared with two control groups of adult patients with typical clinical pictures of psoriasis (n=20; mean age 34.35±3.58 years) and atopic dermatitis (n=10; mean age 41.33±7.35 years).

Results A comparative morphometric analysis of skin biopsy specimens revealed the fewest differences between the analyzed parameters of the squamous epithelium of the patients in the study group and the group with psoriasis. In all three groups, the main mass of the inflammatory infiltrate in the dermis was composed of lymphocytes and macrophages whose numerical density differed in psoriasis and atopic dermatitis at different levels of the dermis, while in the study group it had intermediate values. The number of neutrophils and eosinophils in the study group had minimal values.

Discussion Morphological changes in the epidermis of the study group were closest to those in psoriasis, while the cellular composition of the inflammatory infiltrate of the dermis did not correspond to any of the control groups and had either intermediate values (in terms of lymphocytes and macrophages) or minimal values (in terms of eosinophils and neutrophils).

Introduction The likelihood of adverse perinatal outcome in new coronavirus infection (NKI) COVID-19 increases with the volume of lung tissue damage and correlates with the severity of respiratory failure (DN). Nevertheless, perinatal outcomes and placenta structural changes in pregnant women with critical lung lesions during NKI COVID-19 have been insufficiently studied.

The objective of this investigation was to determine perinatal outcomes and the nature of placental lesions in pregnant women with critical lung injury during novel COVID-19 coronavirus infection.

Material and methods A prospective cohort comparative study was conducted, with subsequent retrospective analysis of perinatal outcomes and the results of histologic examination of the placentas in 53 pregnant women with COVID-19 NCI. Group 1 was composed of 25 women with NKI COVID-19 complicated by community-acquired pneumonia with critical lung injury (KT-4, 76% or more); Group 2 was composed of 28 pregnant women with NKI COVID-19 complicated by community-acquired pneumonia with moderate-to-severe lung injury (KT-2, 25-50%). Perinatal outcomes and the results of morphological examination of the placenta were analyzed using the provisions of the classification of placental injuries developed by the Amsterdam Placenta Workshop Group (2014).

Results In the main group, there were no children born with signs of miscarriage, while in the comparison group there were 8.7% of such children. SARS-CoV-2 antigen was diagnosed in a nasopharyngeal swab immediately after birth in 1 (4.3%) live-born infant in group 2 by PCR. The child died in the postnatal period on the 33rd day of life. Antenatal fetal death in women of Group 1 was the result of marked maternal hypoxia and extremely early PP, in Group 2 - the consequence of placental lesions. A wide spectrum of placental damages, including maternal and fetal malperfusion, maternal and fetal COVID-19 complicated by critical lung injury and with moderate lung injury.

Discussion The placentas of pregnant women delivered due to critical condition do not have pronounced inflammatory and distrophic disorders, being characterized by the phenomena of acute PU. On the contrary, the placentas of women who successfully completed treatment with COVID-19 NKI of moderate severity and safely delivered at late gestational age exhibit the full spectrum of inflammatory and hypoxic lesions, leading to subcompensated and decompensated PU.

Conclusion Weakly pronounced dystrophic processes, lymphocytic infiltration of the decidual and fetal membranes, signs of partial maternal vascular malperfusion and fetal stromal-vascular lesions, and acute PU phenomena were recorded in the placentas of women with NCI COVID-19 and critical pulmonary lesions. The absence of marked inflammatory infiltration of villi and fetal membranes, dystrophic processes, intervillous thrombosis, and villous infarcts realized in decompensated PU in the placentas of these patients was due to the immediate delivery of pregnant women with critical pulmonary lesions in NCI COVID-19. 

Introduction. The stillbirth rate is steadily increasing accounting for about 80 per cent of perinatal mortality in Russia. There is currently no uniform international classification for coding the causes of perinatal death.

The aim of the study was a comparative analysis of the causes of antenatal death of full-term fetuses in the Chelyabinsk region on the basis of various classifications of perinatal mortality to determine possible reserves for reducing the stillbirth rate.

Materials and methods A retrospective case-control study based on the analysis of medical documentation of all cases of antenatal death of full-term fetuses during the period of pregnancy 37 weeks 0 days - 41 weeks 6 days held in the Chelyabinsk region from 2019 to 2021. We use the MedCalc software package (Version 20.110, Belgium, 2022) for statistical analysis.

Results Based on the ICD-10 classification applied to perinatal deaths (ICD-PM), the leading cause of antenatal death of full-term fetuses is acute antenatal complication. In this case, disorders related to duration of pregnancy and growth of the fetus are the main concomitant pathology. There has also been an increase in the proportion of maternal conditions that have a direct impact on antenatal fetal death (placental and umbilical cord pathology) and other diseases or pathological conditions of the mother (hypertensive disorders and infectious and parasitic diseases). According to the Scandinavian-Baltic Classification, most cases fall into category III and are considered preventable. The distribution of full-term fetal death by CODAC showed that antenatal hypoxia of the fetus is rarely the primary and only cause. First comes the pathology of the placenta and umbilical cord.

Discussion The ICD-PM classification allows to lead the most detailed analysis of the causes of antenatal death, considering the pathological conditions of the fetus and the mother, which have a direct influence on the occurrence of the adverse outcome. However, a comparison of the distribution of the cases studied by other classifications showed that the pathology of the placenta and umbilical cord could be considered as the main cause of antenatal death of full-term fetuses, rather than a concomitant cause.

Conclusion The main cause of antenatal death of full-term fetuses in Chelyabinsk region is antenatal hypoxia of the fetus. At the same time, all cases of antenatal fetal death relate to preventable losses, which determines the urgent need to identify predictors of this unfavorable outcome in order to reduce the stillbirth rate.

Introduction Among tumors of lymphatic tissue, T-lymphoblastic lymphoma is a rare disease, with children and adolescents being affected more often. The thymus, lymph nodes and various extranodal localizations are involved in the tumor process, but no descriptions of secondary thyroid involvement in the tumor process in children with primary lymphoma of other localizations were found in the available literature.

The aim of the study was to describe a rare observation of secondary thyroid involvement in mediastinal lymphoma with deciphering of tumor immunophenotype in an adolescent immunomorphological analysis of surgical material.

Materials and methods. We analyzed the archived medical records, data of clinical, laboratory, instrumental and morphological studies of non-Hodgkin’s lymphoma of mediastinal lymph nodes with thyroid involvement. Histological examination of the material stained with hematoxylin and eosin followed by immunohistochemical examination with a set of 16 mono- and polyclonal antibodies was carried out 22 years later on the archive paraffin blocks.

Results Morphological examination of the thyroid biopsy specimen and resectate of its isthmus made pathological and anatomical conclusion: non-Hodgkin’s lymphoma of the thyroid gland, prolymphocytic variant. Thanks to an adequately planned program of polychemotherapy, it was possible to achieve long-term remission with a 22-year recurrence-free survival rate. The retrospective data of clinical, instrumental, laboratory investigations and the results of immunohistochemical analysis of the archived tissue material with the help of a panel of 16 mono- and polyclonal antibodies were compared and the following conclusion was made: C83.5 (ICD-O code 9837/3) upper mediastinal lymphocytic T-lymphoma with secondary damage of the thyroid gland. Complete remission after polychemotherapy with a 22-year recurrence-free survival.

Discussion It was shown that correctly planned treatment on the basis of competent identification of the histo- and cytogenesis of the tumor in the course of well-coordinated teamwork of specialists of different profile (hematologists, pathologists, chemotherapists, etc.) resulted in a favorable outcome. We managed to achieve a long-term remission with no recurrence of the disease for 22 years. By means of immunomorphological analysis, based on the recommendations of new classification of the haemopoietic and lymphoid tissue tumors, at the present stage of medical science development we managed to decode the tumor immunophenotype, which made more concrete, but not refuted the pathological anatomists’ conclusion, made 22 years ago.

Conclusion Analysis of the presented case showed that the tumor immunophenotype corresponded to T-lymphoblastic lymphoma with secondary thyroid involvement. In spite of the fact that in this tumor any extranodal localization is possible, in the available literature we could not find any information about secondary involvement of thyroid in tumor process.

Introduction Chronic endometritis is one of the most important factors leading to reduced fertility in women. The protracted discussion about the presence of this nosology in clinical practice for more than 100 years does not allow to establish the true frequency of chronic endometritis in women of reproductive age. At the present stage, due to the unfavorable demographic situation both in the Russian Federation and in many countries, the study of chronic endometritis, as one of the main determinants of the lesions of the morphological and functional state of the endometrium, is relevant.

The purpose of the study is to determine the current state of the problem of verification of chronic endometritis in women with infertility, reproductive losses and repeated failure of assisted reproductive technologies (ART).

Materials and methods The sources of information were publications from the databases PubMed, Google Scholar, elibrary.ru and Russian medical journals in the field of obstetrics and gynecology, as well as pathological anatomy in the period from 2013 to 2022.

Results and discussion An analysis of the literature showed that chronic endometritis is the cause of infertility, miscarriage and ineffective ART protocols and leads to decrease of the regenerative potential and endometrial reserve. Despite the evidence of the negative impact of chronic endometritis on the reproductive function, at the present stage, the discussion regarding diagnostic approaches to this nosology continues. The use of the histological method of research, as the main and available method for diagnosing the state of the endometrium, is not always allow to verify chronic endometritis, which dictates the need of using high technological methods to confirm and clarify the severity of the pathological process.

Conclusion A unified algorithm for diagnosing chronic endometritis in patients with infertility, miscarriage, ineffective ART cycles and a qualified approach to the morphological diagnosis of the state of the endometrium, standardization of the diagnosis of chronic endometritis, and competent interpretation of immunohistochemical data make it possible to select a pathogenetically substantiated therapy aimed at the rehabilitation of reproductive function.

Introduction Over the past 30 years, sepsis has been an urgent interdisciplinary problem of modern medicine due to the increase in morbidity and a consistently high mortality rate. Patients of oncological hospitals have a high predisposition to the development of sepsis, both in the postoperative period and in the departments of chemo and radiation therapy. In addition, sepsis may be a complication of the postoperative period in patients undergoing surgical treatment. Of interest is not only the clinical and laboratory diagnosis of sepsis in this category of patients, but also the features of its morphological picture, due to uniform diagnostic criteria. The greatest difficulties arise in the study of autopsies, after antitumor chemotherapy, which causes a secondary immunodeficiency condition characterized by the absence of a classical morphological picture of sepsis. The use of modern antibacterial drugs, as well as pathogenetic therapy of sepsis also leads to its pathomorphosis, which also complicates diagnosis.

The aim of the study is to systematize the literature data and the results of our own research on the features of morphological manifestations of sepsis in oncological pathology, depending on cancer treatment.

Material and methods The search and selection of literary sources was carried out in PubMed, GoogleScholar, electronic library systems elibrary.ru, the search depth is 30 years.

Results and Discussion Sepsis in cancer patients after surgical interventions is characterized by hyperergic type of tissue reactions with hyperplasia of lymphoid and myeloid tissue and classic manifestations of septicopyemia of varying severity of purulent metastatic process: from macroscopically distinguishable abscesses to mini-foci of purulent inflammation. Against the background of antibiotic therapy, there is a pathomorphosis of sepsis with a predominance of microcirculation disorders and small focal ulcers. In patients after chemotherapy, accompanied by leukopenia and agranulocytosis, with sepsis, hypoplasia of myeloid and lymphoid tissue is noted, and in the internal organs, along with microcirculation disorders, foci of necrosis, severe dystrophic changes with the absence of neutrophil infiltration are found.

Conclusion Sepsis in cancer patients from pathogenetic positions is heterogeneous, depending on the characteristics of the body and the nature of treatment, it should be divided into hyper- and anergic. The diagnosis of sepsis is clinico-morphological, which requires not only the use of clinical and laboratory diagnostic scales, but also the definition of criteria for morphological diagnosis.