[Histology of fetal lungs at different gestational age]. / Gistologiya legkikh ploda na raznykh srokakh beremennosti.

The lecture is devoted to the morphological characteristics of the maturation of lung tissue structures in the fetal period. Fetal histology of the lungs presents the intrauterine development of lung tissue in four successive stages: pseudoglandular, canalicular, saccular and alveolar, each has specific morphological criteria. The following morphological features are predetermined: the development of alveolar epithelium, the ratio of mesenchyme towards the area in alveolar spaces, the degree of proliferation and location of vessels of the microcirculatory bed towards prealveolar partitions. During the fetal period the alveolar columnar epithelium is flattened and differentiates into alveolocytes type I and II, the area of the mesenchyme gradually decreases and by the birth of a full-term newborn kid it is present mainly in the thickness between the alveolar septa, microcirculation vessels, initially laying deep in the thickness of the mesenchymal tissue, gradually proliferate, approach the pre-alveolar epithelium, channeling it with the formation of alveolar capillary membranes. Air exchange in the lung tissue is mainly provided with two factors: the presence of second-order alveolocytes capable of producing surfactant, and a sufficient formation of alveoli as well. This work summarizes the basics of fetal lung histology with the demonstration of histological preparations of the lungs at different stages of intrauterine development.

[Clinical and morphological diagnosis of secondary hemophagocytic lymphohistiocytosis]. / Kliniko-morfologicheskaya diagnostika vtorichnogo gemofagotsitarnogo limfogistiotsitoza.

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.

[Non-ossifying fibroma (metaphyseal fibrous defect)].

Non-ossifying fibroma (NOF) or metaphyseal fibrous defect (MFD) is benign fibroblast proliferation with the presence of osteoclast-like multinucleated giant cells. The most cases of NOF/MFD occur in the metaphysis of the long tubular bones of the lower extremities, more commonly in the metaphysis of the femur and in the proximal metaphysis of the tibia. This lesion has a characteristic X-ray pattern and requires no surgical intervention, except for cases of a pathologic fracture or a risk for the latter. The paper analyzes 35 NOF/MFD cases in children and adolescents. It has been found that one and all patients have undergone surgery, suggesting the low awareness of this abnormality among radiodiagnosticians, pathologists, and surgeons.

[Osteochondroma in children and adolescents].

Osteochondroma is called a benign cartilage-forming tumor arising from an aberrant subperiosteal cartilage. Multiple osteochondromas syndrome (MOS) is an autosomal dominant disease, the basis for which is mutations in the EXT (EXT1 or EXT2) genes. Osteochondroma is one of the most common benign bone tumors. According to the WHO data, it is detectable in 35% of benign bone tumors and 8% of all surgically removed bone tumors. A total of 491 cases of bone tumors were analyzed in the children and adolescents diagnosed at the Department of Pathoanatomy, Russian Children's Clinical Hospital, Moscow, in 2009 to 2014. All the patients with osteochondroma were divided into 2 groups: 1) sporadic cases (n = 63) and 2) tumors included in MOS (n = 33). Both groups showed a preponderance of boys (39 boys and 24 girls in Group 1 and 21 boys and 12 girls in Group 2). Clinical, radiological, and morphological criteria for the diagnosis and differential diagnosis of osteochondromas in children and adolescents are given.

[The method for the direct evaluation of the state of mucociliary clearance in the children].

The objective of the present study was to develop a readily available, simple to use and acceptable for the application in the childhood method for the evaluation of the state of mucociliary clearance. We have proposed and presented the detailed description of the simple approach to the direct investigation of the ciliary apparatus of the ciliary epithelium cells that requires neither the expensive sophisticated equipment nor the software programs to be implemented. Investigations by this method made it possible to elucidate and identify certain details of the functioning of ciliary epithelium. Other methods for the study of the ciliary apparatus are considered with special reference to their main advantages and disadvantages. Some debatable problems pertaining to the choice of optimal techniques for the evaluation of the functional state of ciliary epithelium are discussed.

[Surgical treatment of rare combination of intestinal malrotation with secondary lymphangiectasia].

The rare combination of intestinal lymphangiectasia with malrotation of the duodenum in a child of three months of life is described. Basing on the literature review only 3 similar cases were described in the world practice. The boy with protein-losing enteropathy was examined at Moscow Scientific Centre of Children's Health. The child had vomiting, diarrhea, loss in body weight, hypoproteinemia, lymphopenia. The infectious nature of the disease was excluded. It had been suggested the Waldman desease (primary intestinal lymphangiectasia). The prognosis for such disease is unfavorable. An examination of the child was continued against the backdrop of ongoing symptomatic therapy. Complete physical examination included monitoring laboratory blood tests, X-ray examination with contrast, CT-scan, gastroduodenoscopy with biopsy of the mucosa of the small intestine. Malrotation duodenum with the recurrent mid-gut volvulus with the development of secondary intestinal lymphangiectasia was diagnosed. Modern methods of examination and multidisciplinary approach made it possible to diagnose the case. Operation to eliminate fixation duodenum resulted in the recovery of the patient. At the present time the child grows and develops according to age and does not require treatment. The prognosis for this disease is regarded as favorable.

[Classical osteosarcoma in children and adolescent].

Classical osteosarcoma is one of the most common primary malignant bone tumors in children and adolescents. It more frequently occurs in the areas of the highest growth plate proliferation: limb long bones particularly in the distal femur (30%), proximal tibia (15%), and proximal humerus (15%). In the long bones, the tumor is located usually in the metaphysis (90%), less frequently in the diaphysis (9%), and very rarely in the epiphysis. This paper considers the clinical, radiological, and histological diagnosis, and prognosis in this pathology.

[OPTICAL BIOPSY FOR DIAGNOSIS OF ESOPHAGEAL MUCOSAL CHANGES IN CHILDREN].

AIM: To analyze the value of confocal laser endomicroscopy in diagnostics of upper gastrointestinal tract mucosa changes in children. PATIENTS AND METHODS: In the current study a total of 116 children aged from 3 to 18 years old undergo conventional endoscopy with confocal laser endomicroscopy supplemented with mucosal biopsy followed by traditional histology in the period from 2011 until 2014. To determine the prognostic value of the of probe based CLE in the evaluation of normal and pathological changes of the esophageal mucosa a comparison of results of optical biopsy with the data obtained during the standard histological examination were performed. RESULTS: After results of probe-based CLE and traditional histology were comprised optical biopsy showed 88.8% sensitivity and 88.3% specificity to esophagitis with Spearmen correlation 0.79 (p = 0.001); 92.3% sensitivity and 95.3% specificity to metaplastic changes of esophageal mucosa with Spearmen correlation 0.85 (p = 0.001); 92.4% sensitivity and 95.2% specificity in differential diagnosis of esophageal polyps with Spearmen correlation 0.95 (p = 0.001). CONCLUSION: Confocal endomicroscopy may become one of the leading methods in pediatric gastroenterology since it allows the endoscopists to inspect the mucosa at the cellular level during the endoscopic procedure and can help in establishing the diagnosis.

[Second-generation colon capsule in small bowel and colon disorders in pediatrics].

BACKGROUND: Aim of the study was to assess the diagnostic yield of second-generation colon capsule in pediatric gastrointestinal diseases. PATIENTS AND METHODS: Five patients with different symptoms of gastrointestinal diseases were included in the study. Among them were: suspicion on diffuse polyposis, intestinal bleeding, lymphangiectasia and inflammatory bowel disease. Image interpretation was made by experienced capsule users, previously trained on small bowel capsule and first generation colon capsule. Lesions or abnormal changes of the mucosa identified on capsule endoscopy served as indications for colonoscopy or esophagogastroduodenoscopy with biopsy or polypectomy if needed. RESULTS: Standard white light endoscopy was made in all children without any adverse events. Second-generation colon capsule allows diagnosing Crohn's disease in small intestine and colon, limphangiectasia of the ileum, single rectosigmoid polyp and diffuse polyposis of the colon. CONCLUSION: Second-generation colon capsule can be used as non-invasive screening method in children without serious complications, thus allowing to differentiate indications for traditional white light endoscopy, which is usually made under general anesthesia in pediatrics.

[Confocal laser endomicroscopy of gastrointestinal tract: history, problems and perspectives in children].

In this review history, principles, technique and clinical applications of confocal laser endomicroscopy are briefly described. This technology allows to expand the diagnostic ability of traditional white light endoscopy and to assess effectiveness of therapeutic procedures in different gastrointestinal diseases. New experimental and clinical data in assessing small bowel barrier dysfunction as a predictor of relapse for inflammatory bowel disease is presented. Problems and perspectives regarding application of optical biopsy for gastrointestinal tract in pediatric practice are discussed.

[Morphological and immunohistogenetical features of colon cancer in children].

We carried out postmortem and immunohistological studies of 3 cases of colon cancer in a 14-year-old (case 1) and an 8-year-old girl (case 2), and Turcot's syndrome in a 14-year-old girl (case 3). Tumors were located in the proximal portions of the colon and they were of rare histological types. The expression of proteins--the products of MLH 1, MHS2, and MHS6 genes responsible for DNA reparation was estimated. There was no expression of MLH1 and MHS6 in cases 2 and 3, respectively. The findings enabled the authors to assign these cases to hereditary polyposis-unassociated colonic cancer that is also a variety of Turcot's syndrome.

[Morphological features of juvenile colon polyps in children]. / Morfologicheskie osobennosti iuvenil'nykh polipov tolstoi kishki u detei.

Histological, histochemical and immunohistochemical studies of 50 solitary juvenile polyps (JP) and 50 JP from children with juvenile polyposis syndrome (JPS) were performed. Observations of the focal complex glandular structures with high mitotic rate were more frequent in JP from patients with JPS (n = 29, 58%) than in solitary JP (n = 17, 34%) (p < 0.03). The immunohistochemical study demonstrated p53 overexpression in individual cells and more than 50% of Ki-67-positive cells in 5 (10%) solitary JP and in 17(34%) JP from patients with JPS (p < 0.007). The finding of microglandular pattern is more typical for JP from patients with JPS. Pathological data, expression of p53 and Ki-67 by immunohistochemistry could help to pick out the group of JP with dysplastic changes.

[Iliac mucosa changes in late periods after total colectomy in patients with syndromes of gastro-intestinal polyposis]. / Izmeneniia slizistoi obolochki nizvedennogo segmenta podvzdoshnoi kishki v otdalennye sroki posle operatsii total'noi koléktomii u bol'nykh s sindromami polipoza zheludochno-kishechnogo trakta.

We studied follow-up iliac mucosa biopsies from 11 patients with juvenile polyposis and 4 patients with familial adenomatous polyposis who had undergone total colectomy with mucosal proctoectomy with creation of straight ileoanal anastomosis. The biopsies that have been taken from the posterior wall of the terminal ileum show incomplete and focal neocolonic transformation of iliac mucosa. Nevertheless, in most cases iliac mucosa preserved its architectural and histochemical characteristics. Chronic inflammation in iliac mucosa is not typical for patients with polyposis.

[Comparative efficacy of laboratory methods for cytomegalovirus detection in autopsy material]. / Sravnenie éffektivnosti laboratornykh metodov vyiavleniia tsitomegalovirusa v autopsiinom materiale.

Eighty eight autopsy specimens obtained from 30 fetuses, still-borns and infants died during the first year of life, all suspected for congenital virus infection at postmortem examination, were studied. The specimens were analyzed by 3 techniques: rapid culture method (RCM) for detection of cytomegalovirus (CMV) infectious activity, the immunocytochemical method for detection of CMV antigen in prints of organs and polymerase chain reaction (PCR) for detection CMV DNA. CMV was detected in 16 out of 26 specimens (61.5%) by PCR, in 43 out of 88 specimens (49%) by RCM and in 15 out of 64 specimens (23%) in prints. The comparison of immune reagents revealed that monoclonal antibodies (McAb) were more specific than polyclonal serum antibodies, as the latter yielded the positive reaction in 10 out of 26 cases (38%), found to be negative in PCR. The data thus obtained indicate that complex techniques, including PCR and RCM in combination with McAb, should be used for evaluation of CMV infection role in child mortality.

[Morphological characteristics of gastrointestinal lesions in patients after total colectomy for colon polyposis]. / Morfologicheskaia kharakteristika porazhenii zheludochno-kishechnogo trakta u bol'nykh posle total'noi koléktomii po povodu polipoza tolstoi kishki.

11 patients with juvenile polyposis and 4 patients with familial adenomatous polyposis after total colectomy entered the study. Long-term follow-up with endoscopic examination and multiple biopsies in these patients showed high probability of polyps in preserved regions of the gastrointestinal tract. Therefore, regular prophylactic endoscopy, morphological examinations and biopsies of endoscopically normal mucous membrane are justified. Such policy is recommended especially for patients with familial adenomatous polyposis.

[Syndrome of enlarged thymus gland in children with congenital heart defects]. / Sindrom uvelichennoi vilochkovoi zhelezy u detei s vrozhdennymi porokami serdta.

Material of the study represents samples of the enlarged thymus of 40 children aged from 1 month to 3.5 years obtained during surgery on the open heart. A thymus enlargement in the majority of children with heart malformations was due to its reactive hyperplasia similar to the first stage of acute (accidental) involution or changes observed in the thymus in the "rebound" phenomenon. In some cases B-lymphocytic hyperplasia was observed which is considered as a sign of the autoimmune disturbances.

[Prospects of reducing perinatal mortality]. / Perspektivy snizheniia perinatal'noi smertnosti.

The paper is concerned with an analysis of the causes of the perinatal lethality, carried out on a material of 2106 autopsies of fetuses and neonates. The authors describe the structure of the perinatal lethality and the relationship between the character of fetal and neonatal pathology and the mother's health status, pregnancy and delivery.

[Morphological changes in the jejunal mucosa in vitamin D-resistant rickets]. / Morfologicheskie izmeneniia slizistoi obolochki toshchei kishki pri vitamin D-rezistentnom rakhite.

Sixteen children with vitamin-D deficiency underwent jejunoscopy with spot jejunal biopsy. Morphologic evaluation of the biopsy specimens provided evidence for glycocalyx destruction and malabsorption syndrome. Hyperactivity of hydrolytic enzymes may be concerned with the adjustment to a disturbance of the calcium/phosphorus metabolism.