Search

Primary pulmonary myxoid sarcoma with EWSR1-CREB1 fusion is an extremely rare tumor. Its clinical manifestation is unspecific and only molecular genetic method can proof this diagnosis. This paper describes an unusual clinical presentation of primary pulmonary myxoid sarcoma in a 68-year-old patient with involvement of both lungs.

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.

Primary melanocytic tumors of the central nervous system (CNS) are extremely rare and account for only 1% of all melanomas and 0.05% of primary brain tumors. In case of diffusely invasive lesions of the pia mater with a tumor of melanocytic origin (without signs of extracranial metastases), the tumors are classified as primary diffuse meningeal melanomatosis (PDMM). The latter is an extremely rare subtype of CNS malignant tumor with an incidence rate of 1 in 20 million people. Despite the development of neuroimaging techniques, today a morphological examination remains the main and most accurate method for verifying CNS melanocytic tumors. The paper describes a fatal case of PMMD manifested as epileptic syndrome, with a rapidly progressive course.

The paper presents the experience of using DNA methylation status in patients with meningiomas of the craniovertebral junction area in a neurosurgical clinic. A clinical case of combined treatment of a patient with meningioma of the craniovertebral junction and the choice of tactics based on the result of DNA methylation analysis of meningioma are described.

Postmortem studies are of great importance in evaluating the effectiveness of clinical, diagnostic, therapeutic, and preventive measures aimed at combating a social disease, such as dyscirculatory encephalopathy, the leading causes of which are hypertension and atherosclerosis. The complexity of these studies is largely determined by a variety of brain changes with the frequent concurrence of hypertension and severe cerebral atherosclerosis and, at the same time, the similarity of some changes, for example, the localization and size of hypertensive and atherosclerotic lacunar infarcts. The paper describes a case of dyscirculatory encephalopathy with multiple small focal cerebral ischemic changes caused by both hypertension and athero-stenosis of several arteries in both the brain carotid systems and the vertebrobasilar system, namely tandem stenoses. It has been established that small infarcts in tandem stenosis can result from adaptive processes in the intracranial arteries. These infarcts have some features of localization, such as the areas of adjacent blood supply to the cerebral hemispheres and cerebellum, as well as the deep regions of the brainstem. It is shown that arterial pathological changes in the ischemic zones permit one to make a differential diagnosis of hypertensive lacunar infarcts and the same infarcts arising in tandem stenoses. In addition, among the typological signs of hypertensive lacunar infarcts, there are enlarged perivascular spaces in the peri-infarct region and ischemic destruction of myelin in the periventricular regions of the brain.

The paper presents an X-ray morphological differential diagnosis of idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (FHP). It describes the etiology, pathogenesis, radiological signs, and pathoanatomy of IPF and FHP. For differential diagnosis, radiological and morphological signs were studied in 105 patients with IPF and in 111 patients with FHP. The mean ages of patients with IPF or FHP were 65.0±8.9 and 48.9±12.3 years, respectively. The history of IPF to the moment of its diagnosis ranged from 1 to 18 months, while that of FHP was 35 to 79 days. The authors describe the additional morphological signs of FHP: delicate collagen fibrosis; smooth muscle metaplasia in the interalveolar septa and fibrotic areas; fibroblastic foci mainly in the walls of bronchioles; plasma cell infiltration of interalveolar septa with a touch of neutrophils and eosinophils. A table has been compiled for differential diagnosis according to the morphological signs of IPF and FHP.

Thyroid-like follicular carcinoma of the kidney (TLFCK) is an extremely rare histological variant of renal cell carcinoma, not yet included in the WHO list of tumors. This tumor has a characteristic morphological structure strikingly resembling follicular carcinoma of the thyroid gland, but differing from itby the immunophenotype of tumor cells. TLFCK is characterized by an indolent clinical course, rarely metastases, and even the presence of metastases does not lead to a worsening of the prognosis for the patient. Described a case of TLFCK diagnosed in a 38-year-old patient, observed clinically for 8 years, without metastases during this time, and removed by focal kidney resection. The paper presents the macroscopic and microscopic characteristics of the tumor, immunohistochemical profile, and discusses the issues of differential diagnosis.

ANCA-associated vasculitides refer to systemic small-vessel vasculitides. The paper shows the role of antineutrophil cytoplasmic antibodies in the development of immune inflammation of blood vessels and tissues. It considers the pathogenesis of granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis and presents the clinical and morphological manifestations of the diseases.

The paper provides a literature review of the differential diagnosis of pathogenetic types of cerebral infarction. It presents a number of features of ischemic strokes characteristic of both cerebrovascular diseases and other nosological entities (tumors, diseases of blood, heart, liver, kidneys, and various other organs). The analysis revealed the leading morphological components characteristic of the main pathogenetic types of cerebral infarctions in the group of cerebrovascular diseases (atherothrombotic, cardioembolic, lacunar, hemodynamic, and hemorheological ones), and of other nosological entities with acute ischemic stroke.

Birt-Hogg-Dubé syndrome is a rare autosomal dominant disease caused by a mutation in the FLCN gene and presents with a triad of multiple fibrofolliculomas, trichodiscomas, and masses that clinically resemble fibroepithelial polyps (acrochordones), accompanied by an increased risk of kidney tumors and lung cysts. The paper provides a literature review supplemented by clinical cases and the morphological pattern of skin lesions. It presents the clinical and morphological features of cutaneous manifestations of the syndrome and gives diagnostic criteria.

The paper describes three cases of soft tissue clear cell sarcoma, a rare melanin-producing malignant tumor, which is diagnosed in 52-to-87-year-old women. It provides a clinical and morphological description of the tumor and the results of immunohistochemical tests.

Immunohistochemical study of breast cancer has been practiced for several decades; however, the standardization of this process has not yet been achieved, despite substantial advances in methodology. The paper presents practical guidelines and standards for testing breast carcinomas, which can be used as day-to-day control of the work of an immunohistochemistry laboratory. It considers the concept of external quality control in the immunohistochemical detection of estrogen (ER) and progesterone (PR) receptors, as well as the problems of harmonization in the immunohistochemical analysis of breast carcinomas, by using the nuclear biomarkers, such as ER and PR, as an example. The agreed standard-based external control in determining the optimal result may yield reproducible data for use in clinical practice.

Inflammatory myofibroblastic tumors of the uterus (uIMT) are rare and difficult to diagnose neoplasms, since the morphological characteristics of this tumor are not specific and are found in other pathological changes. In addition, until recently, specific uIMT markers have not been identified and their diagnostic standards not defined. However, in recent years, there have been more and more studies aimed to identify characteristic morphological, immunohistochemical, and molecular genetic features for the differential diagnosis of uIMT. Recent papers studying uIMT indicate anaplastic lymphoma kinase (ALK) as a potentially reliable marker of uIMT. This communication describes a clinical case of uIMT in a 40-year-old woman who has been preoperatively diagnosed with a large subserous interstitial myomatous nodule. The final diagnosis was made, by analysing a combination of morphological and immunohistochemical signs. This clinical case with a literature review is indicated to consider ALK as a key criterion in the diagnosis of uIMT, as well as the relationship between subsequent treatment and the presence of ALK in the studied tissues.

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor of intermediate malignancy potential, which predominantly affects children and young adults. This paper describes two cases of AFH, as well as a review of literature during 1979 to 2021. It gives data on the epidemiology, clinical features, diagnosis, and genetic characteristics of AFH.

The paper describes an autopsy observation of a 71-year-old male with primary generalized AL amyloidosis lasting about 4 months after its manifestation to the onset of death from hepatic and renal failure. Total damage to the liver and spleen, as well as amyloid deposits in the kidneys, adrenal glands, and pancreas were noted.

Solid pseudopapillary tumor of the pancreas is an extremely rare neoplasm of the exocrine portion of this organ, which affects mostly young women and is characterized by a low malignancy potential and a relatively benign clinical course. According to the literature, even in disease progression as metastases, the overall 5-year survival rate is more than 95%. The paper describes a clinical case of a female patient with a solid pseudopapillary pancreatic tumor regarded as a metastatic neoplasm in the retroperitoneal space after surgical treatment previously performed in 2001.

The paper presents an update on the epidemiology, main clinical manifestations, and diagnostic methods in IgG 4 -associated sclerosing cholangitis. It highlights the importance of morphological and immunohistochemical studies in the diagnosis of the disease. It describes a case of diagnosing IgG 4 -associated sclerosing cholangitis when examining the surgical material from a patient with suspected cholangiocellular carcinoma of the hepatic hilus.

Teratomas belong to a group of germ cell tumors and consist of tissues that are derived from 3 germ layers. The localization of teratomas is extremely diverse. The main task of a morphological study is to diagnose the type of teratoma. According to the WHO classification, there are mature and immature teratomas (ICD-O codes 9080/0 and 9080/3, respectively). It is deemed that the disease prognosis does not depend on the composition of mature tissue components. This paper describes two sectional observations of congenital immature teratomas in a premature live birth infant and a stillborn one. One teratoma, such as epignathus, is a very rare tumor in localization. Emphasis is laid on the need for a thorough teratoma morphological study that defines the tactics of patient management. The described observations demonstrate the importance of timely prenatal diagnosis and an interdisciplinary approach, as well as the need for clear routing of patients with diagnosed fetal space-occupying lesions.

The paper describes a case of a perinatal lethal Gaucher disease in a 29-week-old fetus with non-immune hydrops, facial dysmorphia, hepatosplenomegaly, and hypoplasia of cerebellum and pons. Gaucher cells were found in the lymph nodes, spleen, lungs, thymus, cerebellum, and bone marrow. No storage cells have been detected in the placenta. There was a significant placental weight increase due to swelling. The diagnosis of Gaucher disease was confirmed by biochemical analysis (deficiency of glucocerebrosidase activity and sharply increased hexanoylsphingosine concentration) and molecular genetic techniques (the presence of two mutations of the GBA gene). Our observation shows that characteristic histologic signs of disease can be detected at early stages of development.

The paper presents the life and career of Aleksander Aleksandrovich Bogomolets, outstanding pathophysiologist of the country; famous statesman and public figure; founder of a large scientific school; Academician and Vice-President of the USSR Academy of Sciences; Academician of the UkrSSR Academy of Sciences; Academician of the BelSSR Academy of Sciences; Academician of the USSR Academy of Medical Sciences; Honored Scientist of the RSFSR and UkrSSR; USSR State Prize Winner, and Hero of Socialist Labor.

Triple negative breast cancer (BC) is a heterogeneous group of carcinomas that substantially differ in clinical, morphological, and molecular genetic characteristics, tumor response to chemotherapy, and prognosis. These features define triple negative BC today as a special clinical problem that has not yet been completely solved. The review is devoted to the description and systematization of the currently available literature data concerning molecular and genetic features and differences in a fairly significant group of breast carcinomas with a severe, aggressive course and an extremely poor prognosis. The review presents the existing molecular genetic classification of triple negative BC based on the results of studies conducted by M.D. Burstein (2015) and B.D. Lehmann (2016), which determines the presence of 4 tumor-specific subtypes: basal-like type (type 1 and type 2), mesenchymal, and luminal androgen receptor types. The paper reflects the main stages of transformation of the proposed classification over the past decade and an attempt has been make to describe the molecular characteristics of each subtype of these carcinomas.

The paper describes a case of primordial odontogenic tumor of the mandible, a rare neoplasm that has been recently included into the WHO classification. It presents its clinical, radiological, morphological, and immunohistochemical characteristics.

The paper presents the life and creative career of Professor Alexander Alexandrovich Vasiliev, MD, a prominent Russian pathologist, one of the organizers of Red Army postmortem service, team physician.

The biographical article is dedicated to the memory of Boris Petrovich Ugryumov, a graduate of the Imperial Military Medical Academy (1914), a prominent military pathologist, the First Head of the Department of Pathological Anatomy, Ryazan Medical Institute. The paper presents the major milestones in the life of B.P. Ugryumov; his service on the fronts of the First and Second World Wars and his teaching activity at the Military Medical Academy and the Naval Medical Academy occupy an important place. For about 10 years, he was in charge of the Pathology Department, S.P. Botkin Clinical Infectious Diseases Hospital in Leningrad, which largely determined the area of his professional interests, such as the pathomorphology of infectious diseases, tuberculosis in particular. The archiving and personal photographic documents that have been previously unknown to the public are published for the first time.

Gastric cancer is one of the leading causes of cancer morbidity and mortality worldwide. It is common practice to use two classification systems: the Lauren classification system and the WHO classification of tumors in the morphological study of gastric carcinomas. Since 2010, the WHO classifications have included the term "poorly cohesive carcinoma", which refers to all diffuse forms of gastric cancer, including signet ring cell carcinoma and other subtypes. Despite this, the term has not been widely used in the world community, and it is almost not found in Russian literature. Only recently, after the publication of the 5th edition of the WHO classification (2019), there have been review articles where the term is used, but its name can be translated into Russian in different ways: poor-, weak -, low-adhesive, discogesive. The paper analyzes the Pubmed and Elibrary databases in order to find out the frequency of using various designations for diffuse gastric carcinoma, justifies the use of the term «poorly cohesive carcinoma», and proposes a variant of the term interpretation in Russian.

Tropical malaria is an acute infectious disease from a group of parasitic diseases transmitted by the vector-borne route. Russia registers deaths due to imported malaria. The paper gives brief information on the epidemiology, etiology, and clinical manifestations of the disease and describes the fatal outcome of cerebral tropical malaria, as well as morphological changes in organs and tissues. The K76T mutation associated with drug resistance in parasites was identified in the structure of the plasmodium gene.

The paper presents a case of biphasic (dedifferentiated) osteosarcoma arising primarily on the lung, which has not previously encountered in the literature. It provides a detailed description of its clinical, instrumental, and morphological pattern. It also analyzes the literature on the study of primary pulmonary osteosarcoma and extraskeletal osteosarcoma with high-grade transformation. This clinical case is a clear example of classic biphasic sarcoma interpreted in the context of the phenomenon of biphasic tumors. Their most important aspects (terminology, morphology, biological behavior, and a mechanism of dedifferentiation) are highlighted; the key characteristics of biphasic sarcomas are listed.

The paper presents a unique case of an autopsy study of the concurrence of two diseases, such as liver alveococcosis and hepatocellular carcinoma, in a 46-year-old woman with obvious hypercoagulability syndrome caused by parasitic invasion. It gives the macroscopic and histological characteristics of this case.

Secondary hemophagocytic lymphohistiocytosis (hemophagocytic syndrome, massive macrophage activation syndrome) is a rare, aggressive, severe syndrome with a frequent fatal outcome. The pathogenesis of the syndrome, the role of viral infection, and the development of an excessive, aberrant, and inflammatory response leading to multiple organ dysfunction and sepsis remain unclear so far. The paper presents the data available in the literature and describes the authors' own observation of secondary hemophagocytic lymphohistiocytosis in a 14-year-old girl who had Epstein-Barr virus infection and died of severe multiple organ dysfunction. The in vivo diagnosis was based on the typical clinical presentations of the disease, the detection of the virus by a polymerase chain reaction assay, and the determination of blood ferritin levels. Contemporary morphological diagnostic criteria (immunohistochemical reactions with anti-EBV and anti-CD68 monoclonal antibodies; Epstein-Barr virus encoded RNA (EBER) in situ hybridization) are shown; and clinical and pathological comparisons have been made.

The paper describes a case of chromoblastomycosis, a rare implantation mycosis in the Russian Federation. It gives data on the prevalence, etiology, and clinical presentations of the disease, and the diagnostic possibilities. Emphasis is laid on the leading role of a pathomorphological study in the diagnosis of chromoblastomycosis in non-endemic countries, including Russia. The clinical and pathomorphological presentations are described in detail. Histological examination detected 5-12-µm spherical or polygonal pigmented cells that are fungal elements, which allows chromoblastomycosis to be diagnosed in the cytoplasm of macrophages and extracellularly. A refusal to conduct a pathomorphological study leads to diagnostic errors and an irrational treatment policy.

Dengue fever is acute zooanthroponic infection from a group of vector-borne viral hemorrhagic fevers. Since 2013, Russia has introduced the mandatory registration of dengue fever cases. The paper presents data on the epidemiology, etiology, and pathogenesis of Dengue fever and describes a case of a fatal outcome in severe dengue fever and morphological changes in organs and tissues.

Objective: To reveal the morphological characteristics of simultaneously diagnosed leiomyoma of the corpus uteri and vulva., Subject and Methods: The paper describes a case of multiple uterine leiomyomas concurrent with vulvar leiomyoma in a 39-year-old patient with progressive tumor nodule growth over 2 years. Vulvar tumor was biopsied simultaneously with extirpation of the uterus; vulvar leiomyoma was removed six months later. Histological and immunohistochemical studies: such as hematoxylin and eosin staining, the expression of smooth muscle actin, desmin, and progesterone and estrogen receptors, S100, CD10, and determination of Ki-67 proliferation index, were conducted., Results: The largest (14-cm) multiple tumor nodule in the corpus uteri had the structure of leiomyoma of uncertain malignant potential; the large (8-cm) vulvar tumor was a leiomyoma with hyalinosis. The immunohistochemical profile of uterine and vulvar leiomyoma (smooth muscle actin+, desmin+, progesterone+, estrogen+ receptors, CD117-, and Ki-67) was the same (1-3%). The vulvar leiomyoma was assumed to be a tumor of metastatic origin., Conclusion: Vulvar leiomyoma is rare; it can arise from smooth muscle tissue of various anatomical structures of the skin and soft tissues. The pathogenesis of the so-called metastatic leiomyoma is unclear; there are concepts of a metaplastic transformation of subcelomic mesenchyme and multifocal smooth muscle proliferation. The presented case demonstrates the synchronous development of uterine and vulvar leiomyoma.

The paper describes an autopsy case of a 69-year-old woman with microscopic polyangiitis lasting about 1.5 months despite intensive treatment. She had generalized productive vasculitis, extracapillary productive glomerulonephritis, adult respiratory distress syndrome with focal pneumonia, isolated lung atelectasis, splenic infarction, and toe and finger gangrene. Morphological differences from those of granulomatosis with polyangiitis and Churg-Strauss syndrome are presented.

The paper describes an autopsy case of congenital heart disease as a single ventricle with transposition of the great vessels in a woman who survived to the age of 58 years. Due to hemoconcentration that has compensated for chronic hypoxia, the woman received low-molecular-weight heparin, which was complicated by severe heparin-induced thrombocytopenia resulting in death from cerebral hemorrhage. The author is inclined to explain the unusual clinical course of the disease by the fact that despite the mixing of arterial and venous bloods, transposition of the great arteries in the patient must have been accompanied by the flow of the bulk of arterial blood into the aorta and venous blood into the pulmonary trunk.

Anaplastic thyroid carcinoma is a high-grade aggressive tumor with a tendency for early metastasis. The paper describes a rare case of Stage IVB anaplastic thyroid carcinoma, including its clinical, instrumental, morphological, and autopsy findings, in a 66-year-old woman.

The paper describes 4 autopsy cases of myocarditis in elderly patients with confirmed coronavirus infection. It gives the data of a morphological study of heart specimens and a detailed characterization of a myocardial infiltrate. An immunohistochemical study with cellular infiltrate typing was performed. The fact that lymphocytic viral myocarditis can develop in COVID-19 was morphologically and immunohistochemically confirmed. The features of myocarditis in COVID-19 are the development of the former in the presence of coronaritis and the possibility of its concurrence with lymphocytic endo- and pericarditis.

The paper describes the life of A.I. Polunin (1820-1888), the first professor of an independent department of pathological anatomy in Russia, which was founded at Imperial Moscow University in 1849. It analyzes his doctoral dissertation on cholera and also gives the reviews of his key works. It is noted that the activities of A.I. Polunin as a scientist were greatly influenced by the humoral theory of pathology by Karl von Rokitansky (1804-1878), the doctrine of blood «crases», and by the works of representatives of the Viennese School of physicians who upheld the clinical and anatomical approach in medicine. At the same time, Professor A.I. Polunin is noted to be the first to familiarize Russian physicians with the theory of cellular pathology by R. Virchow (1821-1902).

Parkinson's disease (PD) is a neurodegenerative disease that belongs to a group of cerebral proteinopathies. The main pathomorphological signs of PD are neuronal degeneration in the midbrain substantia nigra and detection of pathological forms of the synaptic protein α-synuclein in the nigral neurons. At the same time, the pathological forms of α-synuclein in this disease have been recently shown to accumulate in the cells of not only the central, but also peripheral autonomic nervous system. The paper provides a clinical and morphological description of a PD case in a 70-year-old patient, which demonstrates that there are typical α-synuclein-positive inclusions in the brain regions (substantia nigra, caudate nucleus, and frontal cortex), salivary glands and colon. The systemic nature of α-synucleinopathy in PD is important in both clarifying the pathogenesis of the disease and elaborating new approaches to its diagnosis and, in the future, to targeted therapy.

This paper reveals the pathogenetic impact of the abnormal gut microbiota on the development of female reproductive system diseases. A dynamic imbalance between the altered microbiota and the macroorganism has many manifestations as hormonal homeostatic disorders, one of which is dysbiosis-induced hypoestrogenemia. Using endometrioid heterotopia as an example, the authors trace the possibility of its progression and malignancy due to the occurrence of primary breakdown of the PTEN tumor-suppressor gene with subsequent genetic abnormalities in the ARID1A and TP53 genes. PTEN mutation in both endometriosis itself and its malignancy indicates that dysbiosis-induced hypoestrogenemia may be implicated in the pathogenesis of endometriosis. Thus, the relationship between female reproductive system diseases and gut microbiome disorders may be more significant; and the possibility of correcting the gut microbiota with prebiotics and probiotics opens new horizons not only in the prevention, but also in the treatment of many gynecological diseases associated with hormone disorders.

The paper gives an update on the pathogenesis and main clinical manifestations of primary (hereditary) hemochromatosis and its diagnostic methods. It emphasizes the importance of genetic research in the diagnosis of the disease. Its clinical manifestations are associated with iron deposition in organs, such as the liver, pancreas, joints, skin, and heart. The paper points out the importance of liver biopsy using Perls' reaction for the diagnosis of liver damage with the development of fibrosis, cirrhosis, and cancer as the main cause of death in patients with hereditary hemochromatosis and presents the results of examining liver biopsy specimens in patients with hemochromatosis.

The paper describes a case of a rare tumor disease with massive involvement of the skin, mainly that of the occipital head and brain and liver tissues in a newborn infant. It considers the morphological and immunohistochemical characteristics of a giant tumor cell nidus in the skin of the occipital head.

Trichilemmal carcinoma is a rare skin tumor that mainly occurs in the elderly (mean age, 71 years) and is localized in the repeatedly sun-exposed areas, most commonly on the face, scalp, neck, and dorsa of the hands. Its differential diagnosis is made with squamous cell skin cancer, clear-cell porocarcinoma, hidradenocarcinoma, and melanoma. The prognosis of trichilemmal carcinoma is most favorable than that of other skin tumors during radical removal. The paper describes a case of an 80-year-old man with long-standing trichilemmal carcinoma of the skin in the area of the shoulder joint, which is concurrent with squamous cell cancer in another area of the skin.

The paper describes 11 cases of local tumor-like amyloidosis (LTA) of the upper respiratory tract, among which laryngeal amyloidosis was most common. The clinical diagnosis of suspected local amyloidosis was made in only two cases. The diagnosis of local amyloidosis was established at a morphological examination of a distant neoplasm, by using special Congo red staining followed by polarizing microscopy. Attention is drawn to the localization and sequence of amyloid deposition and morphological changes related to the age of patients and the duration of the disease. The paper discusses the nature of local amyloidosis as stromal vascular proteinosis with the deposition of AL amyloid (immunoglobulin light chain amyloid) that are formed apparently by local immunocytes of the mucosa-associated lymphoid tissue (MALT) system. It emphasizes the need for the clinical monitoring of patients with LTA to rule out systemic amyloidosis.

The paper presents new Russian and foreign materials on cytotrophoblastic invasion, the most important mechanism of interaction between the placenta, fetus, and mother during the progression of physiological pregnancy. The original classification of placental cell development has been published; the initial wave of invasion, the main and additional ways of its implementation in the second trimester, and the formation of cytotrophoblastic plugs in the spiral arteries, and the fate of multinucleated giant cells have been characterized. Additional sources of invasive cells in the second trimester are presented. A general concept of cytotrophoblastic invasion as a regulator and main mechanism of transition from the histotrophic to more effective hemochorial type of fetal nutrition has been made. The modern definition of an invasive process is given. This information is important for obstetricians and pathologists who analyze the causes of obstetric complications.

Granulomatous diseases are a heterogeneous group of the diseases of different etiology, which are manifested by a variety of clinical syndromes and variants of tissue changes, by non-uniform sensitivity to therapy and by the predominance of the common dominant histologic sign - the presence of granulomas that determine the clinical and morphological essence of each disease. Granuloma is a chronic inflammatory response, which involves macrophages and other inflammatory cells. After antigen exposure, the activation of T lymphocytes, macrophages, epithelioid cells, and multinucleated giant cells results in granuloma formation. Granuloma also contains the extracellular matrix produced by fibroblasts, which can demarcate and isolate the antigen. Granulomatous diseases are classified by their etiology as infectious and non-infectious. However, recent investigations demonstrate that pathogenic microorganisms can cause granulomas in the diseases previously considered non-infectious. In some cases, it is very difficult to classify a granulomatous process as infectious and non-infectious. The aim of this paper is to draw the attention of readers to the diversity of granulomatous diseases, to describe the key points of pathological and anatomical manifestations of various infectious diseases, and to determine an approach to the differential diagnosis of granulomatoses.

The paper considers one of the types of intranatal fetal hypoxia - circulatory hypoxia. It discusses the issues of fetal head configuration during childbirth and the compensatory-adaptive mechanisms when the fetal head passes through the maternal parturient canal. The relationships and differences between circulatory hypoxia and birth trauma are investigated.

Lambl's excrescences are a rare disease that is characterized by a lesion of the heart valves as filamentous growths on their surface mainly along the coaptation lines and that is mostly asymptomatic. Due to traumatic injuries during heart contractions, fibrin masses can be deposited on the surface of the growths, contributing to thromboembolic events or infection. The paper provides the data available in the literature and demonstrates a postmortem observation of Lambl's excrescences on the ventricular surface of the mitral valve concurrent with myocardial infarction.

Sarcoidosis is a multisystem disease of unknown etiology, characterized by specific granulomas without caseous necrosis in the affected organs and tissues. Along with respiratory organs, the gastrointestinal tract may be affected by sarcoidosis. Due to the rarity of gastric involvement of sarcoidosis, substantial difficulties arise in verifying the diagnosis, making a differential diagnosis, and examining gastric biopsy specimens. The paper describes in detail pathological changes in the gastric wall tissue specimen in sarcoidosis and comparatively analyzes the findings with the data available in the literature.