Arkhiv patologii最新文献

The paper discusses changes in the structure of the classification, criteria for the diagnosis of lymphoid neoplasms in the 5th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (2022). Changes are presented regarding new nosological units, renaming and abolition of some previously existing ones. The importance of molecular genetic studies in the isolation of many lymphomas and the need to apply these studies in everyday clinical practice are emphasized. Lymphoid precancerous processes and lymphoid proliferations introduced into the Classification for the first time are considered.

Background. The novel coronavirus infection (COVID-19) often manifests in children as diarrhea, vomiting, abdominal pain, and some children develop acute appendicitis. To elucidate the role of SARS-CoV-2 in the development of acute appendicitis, a more detailed study of the presence of its genetic material in the tissue of the appendix.

Objective: Determination of SARS-CoV-2 RNA in appendices of children with COVID-19 by fluorescence in situ hybridization (FISH).

Material and methods: A retrospective analysis of case histories and morphological analysis using FISH of appendices of pediatric patients with established clinical diagnosis of acute appendicitis and confirmed infection with SARS-CoV-2 was performed. The material was divided into 3 groups: 1st -appendices obtained during appendectomy in children with established clinical diagnosis of «coronavirus infection» (COVID-19, PCR+) (n=42; mean age 10.8 years); 2nd - appendices of children (n=55; mean age 9.7 years) with acute appendicitis obtained before the onset of the COVID-19 pandemic; 3rd (control) group (n=38; mean age 10.3 years) - autopsy material of the appendices (intact).

Results: In all samples of the appendices of the 1st group, a positive SARS-CoV-2 viral RNA signal was noted in the cytoplasm of most epithelial cells and single immunocompetent cells. The signal intensity remained the same in all slides, regardless of age. In all samples obtained from patients without COVID-19 (groups 2 and 3), confocal microscopy did not reveal a signal, which indicates successful adaptation of the FISH method in this study and excludes the false positive results.

Conclusion: In the epithelium of the appendices of children of different age with COVID-19, the FISH method revealed SARS-CoV-2 RNA, which does not exclude the association between viral invasion and the development of acute appendicitis.

Atypical fibroxanthoma (AFX) is a rare skin tumor characterized by a combination of a «malignant» morphological features and non-aggressive clinical course. Diagnosing AFX is challenging due to histological «diversity» and heterogeneous immunophenotype. The presented review describes the history and evolution of AFX as a nosological form of cancer, its histogenetic origin, pathogenesis and biological potential. The clinical, morphological, immunohistochemical, molecular cytogenetic characteristics and histological subtypes of the tumor as well as differential diagnosis have been presented in detail.

Objective: Evaluation of structural and immunohistochemical features of cornea in Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK).

Material and methods: Group 1 - 44 patients (46 eyes) with FECD, group 2 - 42 patients (42 eyes) with BK. All patients underwent keratoplasty. Preoperative anterior segment optical coherence tomography (AS-OCT, RTVue-100, Optovue, USA) was performed. Endothelium-Descemet membrane (EDM) complexes, corneal buttons were obtained intraoperatively. Morphological (H&E staining) and immunohistochemical (primary antibodies to pancytokeratin, vimentin, fibronectin) studies were performed at the light microscope level (Leica DM-2500, Leica Application Suite V4.8, Leica Microsystems, Switzerland).

Results: A direct correlation is found between the results of DM analysis in vivo with OCT and ex vivo with light microscopy. DM thickness (AS-OCT) was significantly greater in FECD (23.0 [19.0; 27.0] μm), than in BK (13.0 [12.0; 14.0] μm). Morphological study of EDM and corneal buttons showed similar difference in DM thickness: 17.9 [16.1; 20.0] μm in FECD and 11.9 [11.3; 13.0] μm in BK. Irregular optical density of stroma is a feature of edema and local fibrosis. In FECD and BK pancytokeratin is expressed in epithelial and endothelial cells, vimentin - in keratocytes, macrophages and vascular endothelium, fibronectin - in DM. In FECD, vimentin is expressed in endothelial cells.

Conclusion: FECD and BK are associated with different DM' and endothelium' abnormalities, which lead to similar changes of stroma and epithelium. AS-OCT is a useful method of FECD and BK in vivo diagnostics and the selection of treatment option.

The review summarizes data on the features of antigen presentation in tumor cells. The molecular mechanisms of the antitumor immune response are considered with an emphasis on the ability of tumor cells to avoid the action of immune surveillance. The features of expression of MHC molecules depending on treatment regimens are provided. Ways to improve existing and create new treatment regimens aimed at elimination of tumor cells because of antitumor immune response are discussed.

Patients with damage of the mitral, aortic and tricuspid valves and systolic myocardial dysfunction associated with previous SARS-CoV-2 infection are described. The diagnosis of acquired defect was established in 4 patients based on medical history, electrocardiography, echocardiography, magnetic resonance imaging of the heart, endomyocardial or intraoperative myocardial biopsy, and in one case, autopsy. The study of the myocardium included H&E, Van Gieson staining, immunohistochemical (IHC) study with antibodies to CD3, CD20, CD45, CD68, to the nucleocapsid and Spike proteins of SARS-CoV-2. Previous valve diseases (prolapse, bicuspid aortic valve) served as a background for the development of the defect in 2 patients. In all cases, IHC studies revealed coronavirus proteins, lymphocytic endocarditis and myocarditis, moderate fibrosis, and signs of connective tissue disorganization. High titers of anticardiac antibodies indicated an autoimmune mechanism for carditis. No signs of infective endocarditis or thromboembolic complications were identified in any case. In patients with an unclear nature of valvular heart defects, a previous new coronavirus infection should be identified and taken into account as a possible etiological factor. The simultaneous development of lymphocytic myocarditis significantly increases the risk of surgical intervention on the valves and requires an integrated approach to treatment.

Anti-angiogenic drugs are used as an established approach of malignant neoplasms therapy. It has been established that the development of the phenomenon of vasculogenic mimicry - a specific variant of tumor neoangiogenesis, which is formed in highly aggressive solid tumors, is associated with a decrease in the effectiveness of antitumor therapy. This review highlights the mechanisms of development of vasculogenic mimicry in malignant neoplasms, which is one of the alternative options for tumor blood supply. In the formation of vasculogenic mimicry, an important role is assigned to the tumor microenvironment, primarily tumor-associated macrophages and fibroblasts. The signaling pathways that regulate the formation of vasculogenic mimicry channels in tumors have been characterized. The prospects for a targeted impact on molecular targets that initiate and promote vasculogenic mimicry, the impact on which can increase the effectiveness of antitumor therapy, are shown. The review discusses experimental studies of the mechanisms of vasculogenic mimicry formation in malignant neoplasms and the prospects for targeted action on molecules that are components of signaling cascades involved in the development of this model of neoangiogenesis.

Mast cells (MCs) are highly differentiated and multifunctional immune cells. The importance of TC has been established not only as mediators of allergic reactions, but also for the development of an immune response, the occurrence of certain autoimmune diseases, tissue homeostasis, the formation of immunotolerance and metastasis of malignant tumors. MCs are present in the endometrium of women in various value depending on age, the phase of the menstrual cycle, the presence of pregnancy. Out of pregnancy, MCs are involved in the cyclic transformation of the uterine mucosa. At the onset of pregnancy, MCs stimulate the process of remodeling of the spiral arteries, the production of leukemia-inhibiting factor (LIF), which is the main implantation factor, and contribute to the formation of an immunotolerant state of the mother in relation to the fetus. Obstetric complications are accompanied by a variable content of MCs, which is associated with different genesis of diseases. A low amount of MCs is associated with impaired implantation and the development of early preeclampsia, an increased content of MCs is observed in the presence of a pathological inflammatory reaction that accompanies late preeclampsia. This review is devoted to the significance of MCs and their mediators in the physiological course of pregnancy, as well as their participation in the pathogenetic mechanisms of pregnancy complications.

IgG4-related disease is a chronic autoimmune fibro-inflammatory disease characterized by the presence of lymphoplasmacytic infiltrate, storiform fibrosis, obliterating phlebitis, increased number of IgG4+ cells in tissue, and, in most cases, an elevated serum IgG4 level. This disease often affects the pancreas, salivary glands and lymph nodes, but can involve almost any tissue. Its etiology is still unclear, the central role in the pathogenesis belongs to B-lymphocytes, T2-helpers, interleukins 1-β, 4, 5, 10, 13 and tumor growth factor 1-β. The ambiguous clinical picture and frequent simultaneous involvement of several organs make it difficult to diagnose, so biopsy plays a leading role in making a diagnosis. The characteristic microscopic picture, the presence of certain populations of lymphocytes are key criteria in establishing the correct diagnosis.

Chronic gastric ulcer is a rare disease in childhood. The article presents data on the epidemiology and etiology of the disease in children, describes the case of a chronic gastric ulcer complicated by penetration into the liver, perforation, development of abdominal sepsis, with a fatal outcome in a 7-year-old girl.