Background: Choriocarcinoma is an aggressive trophoblastic malignancy characterized by rapid progression and a strong tendency for early hematogenous metastasis. It may occur in gestational or nongestational forms. Nongestational choriocarcinoma is extremely rare and is most commonly reported in young women. The tumor frequently metastasizes early to organs such as the lungs, liver, and brain. Case presentation: We report the case of a 21-year-old woman who presented with dyspnea and hemoptysis and was initially treated for pneumonia. Further evaluation revealed nongestational choriocarcinoma with pulmonary and hepatic metastases. Diagnosis: Contrast-enhanced computed tomography of the chest initially suggested pulmonary artery thromboembolism; however, the diagnosis was ultimately confirmed by histopathological examination. Conclusion The distinctive feature of this case is that the disease presented with clinical and radiological findings mimicking pulmonary artery thromboembolism. This case highlights the importance of considering metastatic choriocarcinoma in young women presenting with unexplained respiratory symptoms, hemoptysis, and atypical pulmonary vascular findings.

Introduction: Preeclampsia disease represents a spectrum of hypertensive disease in pregnancy, beginning with gestational hypertension and progressing to develop severe features, ultimately leading to its more severe manifestations, such as eclampsia and HELLP syndrome. In Mongolia, the incidence of preeclampsia was 26.3% in 2020. In our country, the International Amsterdam Consensus Guidelines have been adopted since 2022, and the placenta has been evaluated according to these guidelines. Goal: To evaluate the pathological changes in the placenta of pregnant women with preeclampsia according to the Amsterdam guidelines and compare them with healthy pregnant women. Materials and method: This study was conducted using a retrospective, case-control design. Based on clinical data, 100 placentas from pregnant women with pre-eclampsia and 100 placentas from healthy pregnant women were randomly selected from the 1046 placentas that arrived at the Laboratory Department of the National Center for Mothers, Newborns and Women. The study was conducted after obtaining approval from the research ethics committee of “Ach” Medical University.
Statistical analysis of study results: Data collected during the study were analyzed using SPSS software [Version 26.0, SPSS Inc., Chicago, IL, USA]. Study parameters were calculated using descriptive statistics; the impact of factors influencing pre-eclampsia was assessed via logistic regression analysis with 95% confidence intervals, and a P-value <0.05 was considered statistically significant. Pearson’s Chi-square test was used to analyze placental morphometric parameters, and Pearson’s correlation was used to assess the relationships between various placental structural characteristics Ethical approval: The study was reviewed and approved by the Medical Ethics Committee of "Ach" Medical University during its meeting on February 11, 2026, and was conducted following the receipt of ethical approval. Results: Our study included placentas from 200 individuals aged 18-45 years. Placental weight was statistically significantly lower in severe preeclampsia than in mild preeclampsia [390.8±66.4 g vs 489.7±52.0 g, t=8.32, p<0.001]. This indicates that as the severity of the disease increases, the proliferation tends to be delayed. Multiple logistic regression analysis showed that decidual arteriopathy was 70 times more likely to be associated with the predisposition to preeclampsia [OR=69.7; 95% CI: 18.5–261.3; p<0.001], and Accelerated villous maturation was 30 times more likely to be associated with the predisposition to preeclampsia [OR=24.9; 95% CI: 2.8–221.7; p=0.004]. Conclusion
1. When comparing the gross structure of the placenta in the two groups, in the preeclampsia, the placental weight and length were reduced, while the rate of para-marginal placental umbilical cord insertion site was statistically significantly increased.
2. When comparing the histological changes of the placenta in the pre-eclamptic and healthy groups, the incidence of infarction, distal villous hypoplasia, accelerated villous maturation, and decidual arteriopathy was statistically significantly higher in the pre eclamptic group.
3. Placental weight loss was 2-fold, decidual arteriopathy was 70-fold, and accelerated villous maturation was 30-fold which contributed to the predisposition to preeclampsia pregnancy.

Background: The assessment of patients’ quality of life has emerged as a critical metric in evaluating healthcare services. Internationally, numerous studies have been conducted to assess the QoL of individuals diagnosed with pulmonary embolism through the development of standardized questionnaires and their association with various clinical parameters. Aim: To adapt a standardized questionnaire for assessing the quality of life following a pulmonary embolism and to evaluate the quality of life of affected patients. Materials and Methods: A total of 33 patients diagnosed with pulmonary embolism and hospitalized in the Department of Pulmonology at the Third State Central Hospital in Mongolia between August 2022 and December 2023 were included in the study. An observational cross-sectional study design was used. Inclusion criteria encompassed all patients diagnosed with PE during the study period, while exclusion criteria included individuals with severe comorbidities, those aged over 85 years, and those who declined participation. QoL was assessed using the Pulmonary Embolism Quality of Life (PEmb-QoL) questionnaire, which consists of 39 questions categorized into six domains. Higher scores indicate poorer QoL. Data analysis was performed using SPSS version 16. Results: The average age of the participants was 61±15 years, and 18 (54.5%) were female. The median duration of anticoagulant therapy was 170 days (range: 27–2555 days), and the average monthly expenditure on medication was 80,000 MNT (range: 63,000–400,000 MNT). The overall mean QoL score was 69.7±23.2. The median scores for the six domains were as follows: frequency of complaints 1.6 (IQR 1.5-1.9; max 5 score), activities of daily living limitations 1.5 (1.3–1.8; max 3 score), work-related problems 1.7 (1.5–2.0; max 2 score), social limitations 2.0 (2.0–3.0; max 5 score), intensity of complaints 3.0 (3.0–4.0; max 6 score), emotional complaints 2.0 (1.5–2.4; max 6 score). The internal consistency reliability of the questionnaire was assessed, with the symptom frequency category scoring well (α=0.74), while the other categories had excellent reliability (α>0.85). A weak positive correlation was observed between overall QoL scores and age, while a weak negative correlation was identified with body mass index (r=0.14 & r= -0.13, P>0.05). Conclusion The study findings indicate a low QoL among PE patients, emphasizing the necessity for enhancements in post-diagnosis medical care and long-term management strategies to improve patient outcomes.

Background: Respiratory viral and bacterial infections are one of the leading causes of hospitalization and death worldwide, particularly affecting children, the elderly, and immune compromised individuals. The detection of causative pathogens is crucial for understanding the epidemiology, prevention, management, and treatment of severe pneumonia. Molecular diagnostic methods provide high sensitivity and speed, enabling the simultaneous detection of viral and bacterial co-infections. Aim: Detection of single and combined viral and bacterial infections in hospitalized children with pneumonia using multiplex PCR. Materials and Methods: We conducted a cross-sectional study design involving 100 hospitalized participants at the National Center for Mothers, Newborns, and Women II. The study utilized questionnaires and laboratory analysis methods. Nasopharyngeal swabs were collected from the participants using a sterile swab and transported in a UTM transport medium (Jiangsu, China). After nucleic acid extraction using the STARMag 96 ProPrepC assay, the samples were analyzed with the Seeprep 32 automated analyzer (Seegene Inc., Korea). Real-time polymerase chain reaction (PCR) analysis was performed using the Allplex™ RV Master Assay and Allplex™ PneumoBacter Assay (Seegene Inc., Korea), with the CFX-96 system (BioRad Inc., USA). Results: The prevalence of viral infections in the study population was as follows: influenza type A 3% (n=3), influenza type B 3% (n=3), total influenza virus 14% (n=14), respiratory syncytial virus 18% (n=18), adenovirus 10% (n=10), rhinovirus 20% (n=20), and SARS-CoV-2 5% (n=5). No bacterial infections, such as B.parapertussis or L.pneumophila, were detected. However, bacterial infections identified included B.pertussis in 1% (n=1), C.pneumoniae in 2% (n=2), H.influenzae in 43% (n=43), M.pneumoniae in 52% (n=52), and S.pneumoniae in 45% (n=45). Of the 100 children in the study, 6% had influenza or influenza-like illness. Among these, 43% had the virus alone, and 14% had a viral co-infection. Bacterial infections were detected individually in 40% of cases, with co-infections in 46% of bacterial cases. Conclusion Metapneumovirus, B.parapertussis, and Legionella pneumophila were not detected in the study participants (0%). Among the viral infections, respiratory syncytial virus (18%, n=18) and rhinovirus (20%, n=20) had the highest prevalence. For bacterial infections, H.influenzae (43%, n=43), M.pneumoniae (52%, n=52), and S.pneumoniae (45%, n=45) were most commonly detected.

Background: The annual incidence of pulmonary thromboembolism is reported to be 39–115 cases per 100,000 population, with rates of 60–120/100,000 in Western countries and 10–20/100,000 in Asian countries. In Mongolia, few studies revealed the prevalence of risk factors and clinical manifestations of acute pulmonary embolism. Over the past 30 years, the incidence of risk factors for non-communicable diseases, which are mainly triggered by lifestyle and social parameters, has rose. Moreover, environmental conditions such as cold climate, hypoxia, and blood hyperviscosit may contribute to higher incidences of acute pulmonary embolism in high-altitude regions. This condition is potentially fatal and can become impair quality of life. Aim: We aimed to compare risk factors and clinical characteristics based on age and sex, and to evaluate laboratory findings and diagnostic tests among Mongolian patients diagnosed with acute pulmonary embolism. Materials and Methods: This retrospective research included total 232 patients meeting inclusion criteria. The information was collected from patient histories, including general demographics, risk factors, comorbidities, symptoms, and physical examination findings. Laboratory analyses included complete blood count, coagulation profile, and immunological markers (D-dimer, NT-proBNP, troponin, protein C, homocysteine, and C-reactive protein), as well as selected imaging parameters. We used Wells and Geneva scoring systems to assess probability of acute pulmonary embolism and Pulmonary Embolism Severity Index to determine disease severity. Differences by age and sex were analyzed using independent t-tests for continuous variables and chi-square tests for categorical variables. Results: Among participants with acute pulmonary embolism, the prevalence of tobacco and alcohol use was significantly higher among males (p<0.001). Among comorbidities, arterial hypertension and other pulmonary diseases were more common in males, whereas cardiac diseases were more frequent in females (p=0.028). Participants aged 65 years and older showed higher rates of comorbid conditions and regular medication use (p<0.001). The most common symptoms were dyspnea (90.9%), chest pain (74.2%), cough (70.5%), leg pain (38.9%), hemoptysis (20.7%), and cyanosis (9.3%). According to sPESI scoring, 69.8% (n=162) were at high risk of death within 30 days, with no significant difference by sex. However, mortality risk within 30 days was significantly higher in participants aged 65 years and above (p<0.001). As increasing age, the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were elevated, indicating an acute inflammatory response (p=0.001). Contrast-enhanced CT scans revealed that 95 participants (44.2%) had main pulmonary artery involvement, with no significant sex difference, though involvement of the main pulmonary artery was more frequent in those aged 65 and older. Conclusion Dyspnea, chest pain, and cough were the most common symptoms among patients diagnosed with acute pulmonary embolism. The 30-day mortality risk associated with it was higher among males and increased with advancing age.