Background: Lung cancer remains the leading cause of cancer-related mortality worldwide, accounting for approximately 1.8 million deaths annually and representing 18% of all cancer deaths¹. According to the GLOBOCAN 2024 report, 2.4 million new cases were registered globally, ranking second after breast cancer². Non-small cell lung cancer (NSCLC) constitutes 85% of lung cancer cases, with adenocarcinoma being the most common subtype³. The objective of this study is to map the prevalence of HER2 activation and mutations in EGFR, EML4-ALK, ROS1, BRAF, and KRAS genes among lung cancer patients in Mongolia, and to evaluate their correlations with clinical and morphological parameters (age, sex, smoking status, stage, and morphology). Aim: To determine the distribution pattern of HER2 activation and EGFR, EML-ALK, ROS1, BRAF, KRAS gene mutations among patients with lung cancer in Mongolia, and to evaluate their associations with clinical and morphological characteristics. Materials and Methods: A retrospective study was conducted using archived materials from lung cancer patients at the Clinical Pathology, Molecular Genetics, and Pathology Laboratories of the National Cancer Center of Mongolia, covering the period from 2019 to June 2025. DNA Extraction from Tumor Tissue: Formalin-fixed paraffin-embedded (FFPE) tissue blocks from patients diagnosed with lung cancer, stored in the pathology department archives, were selected for the study. Sections of 5–10 μm thickness were cut, mounted on glass slides, stained with hematoxylin and eosin (H&E), and reviewed by a pathologist. Areas containing ≥20–30% tumor cells were identified and macro-dissected for analysis. Real-Time PCR Assay for Detection of EGFR/BRAF/KRAS/EML4-ALK/ROS1 Mutations: EGFR mutation detection was performed using the PANAMutyper™ EGFR Mutation Detection Kit (Panagene, Daejeon, South Korea) according to the manufacturer’s instructions. PCR reactions were carried out on a compatible instrument (Roche LightCycler 480, Germany) as recommended by the manufacturer. Statistical analysis was performed using Prisma-10 software. Results: A total of 282 lung cancer cases were included in the study. EGFR mutations were detected in 44% of cases and were absent in 56%. No significant age-related differences were observed (p=0.2636); however, EGFR mutations were significantly more frequent in females (36.6% vs. 19.6%, p=0.0019). No statistically significant differences were found across disease stage, T, N, or M classifications (p>0.05). No association was identified between smoking status and EGFR mutations (p=0.4178). Morphologically, EGFR mutations were significantly more prevalent in adenocarcinoma (54.83%) compared to squamous cell carcinoma (SCC) (31.8%; p=0.002). Of the 282 cases, adenocarcinoma accounted for 155 (54.9%) and SCC for 116 (41.1%). Overall, EGFR mutations were positive in 43.97% of cases, with a higher prevalence in adenocarcinoma (24.82%) than in SCC (13.1%). By exon: - Exon 18 mutations were detected in 6% of cases, predominantly in adenocarcinoma (6%, 4.25%). - Exon 19 mutations occurred in 8.15% and are associated with sensitivity to targeted therapy. - Exon 20 mutations were found in 3.19%, with the T790M resistance variant in 1.77%. - Exon 21 mutations were observed in 9.57%, more common in adenocarcinoma (9.57%) than in SCC (3.19%). Survival analysis stratified by stage at diagnosis showed significantly longer median survival in early-stage patients (18.6 months). Kaplan-Meier curve comparison, log-rank test, and hazard ratio calculations confirmed statistically significant differences (p < 0.05), indicating that disease stage is a key prognostic factor. Conclusion The study findings reveal a high prevalence of EGFR mutations among Mongolian patients with lung adenocarcinoma, underscoring the need for widespread implementation of targeted therapy (EGFR-TKIs). In contrast, mutation rates were lower in SCC and other morphological subtypes, highlighting the importance of investigating alternative molecular markers in these subgroups.

Background: Vulnerable populations at risk of micronutrient deficiencies include children and women, especially pregnant women, lactating mothers, infants and young children. According to WHO guidelines, a population with a micronutrient (vitamin and mineral) deficiency of more than 20% is considered a public health problem.
Although Mongolia has made significant progress in improving the nutritional status of the population, especially children and women, the 2024 VI survey found that micronutrient deficiencies are high among pregnant women.
The MMS (Multi-ingredient Micronutrient Supplement) distributed to pregnant women by soum and household health centers contains all the essential vitamins and minerals for pregnant women, but coverage has remained inadequate for more than 10 years. Goal: To establish the prevalence of micronutrients deficiency in pregnant women Materials and Methods: Totally 2796 pregnant women included in cross-sectional study from urban and rural area. Survey procedures consisted of interview, anthropometric measurements, clinical examinations, and the collection of biological (blood and urine) samples for pregnant women. Micronutrient deficiencies were assessed by tests for hemoglobin, serum, ferritin, soluble transferrin receptor (sTfR), 25-hydroxyvitamin D {25(ОН)D}, spot urine samples for determination of urinary iodine concentration. Statistical processing : The data from the survey questionnaires were entered into a database created in the “EpiData 3.1” software environment. The data created and verified in the EpiData software environment were converted to the “SPSS–25” program, and statistical analysis was also performed using the SPSS-25 program. The results table was prepared using Microsoft Word 2021 and Microsoft Excel 2021 programs. Research ethics: The research methodology was discussed at the meeting of the Medical Ethics Review Committee under the Ministry of Health on 2023.03.27 (23/017), and permission to conduct the study was obtained Result : The prevalence of anemia, as measured by hemoglobin, was 22.3% and the iron deficiency anemia (IDA), as measured by adjusted serum ferritin or soluble transferrin receptor (sTfR) was (39.8%/9.0%). Prevalence of iron deficiency as measured by serum ferritin was also highest in Western 41.9% and lowest in Khangai region 40.2% (P<0.01). The prevalence of vitamin D deficiency among pregnant women was high at 92.5%, and 7.5% of all pregnant women had adequate vitamin D status. The median concentration of 76.4µg/l indicates inadequate iodine status in pregnant women, as the desired range for adequate iodine nutrition in pregnancy 150-249 µg/l. Conclusions 1. 22.3 percent of pregnant women are anemic, and the prevalence of anemia has not decreased from 2017 levels and remains common.
2. The prevalence of iron deficiency (as measured by ferritin levels) was 39.8 μg/L and the soluble transferrin receptor level was 9.0 μg/L, which is higher than previous studies.
3. The prevalence of vitamin D deficiency among pregnant women remains common, with 76.6% having severe or moderate deficiency, and 15.9% having mild deficiency.

Background: Men’s health is a vulnerable associated with higher risk behaviors and is less considered to their health compared to women. According to NSO, of the total population, 49.3 percent were males and 50.7 percent were females in Mongolia. There is a difference in average life expectancy between man and woman, and males live in average eight years (9.2) fewer compared to females. Objective: To determine nutrition status among men aged 15-49 in Mongolia Materials and Methods: The target population was divided into 5 strata based on Mongolia’s socio-economic regions and Ulaanbaatar City. 1950 men aged 15-49 were randomly selected. The confidence interval was set at 95%, with a precision of ±5% or less for all indicators. The sample size was sufficient to obtain representative data on the nutrition status of men at the national level and to calculated using WHO recommendation for adults. Ethics consideration: The survey methodology was discussed at the Scientific committee of National Center for Public Health, on February 6, 2023. Ethics approval was obtained from Medical Ethics Review Committee under the Ministry of Health on March 27, 2023. All participants were participated voluntarily and written informed consent were obtained from participants. Results: The prevalence of overweight and obesity among men was 57.4%, with 17.0% classified as obese. Overweight and obesity rates were highest in men aged 30-39 years (62.2%) and 40 49 years (64.5%) among other age groups. Conclusion In Mongolia, the prevalence of overweight and obesity among men aged 15–49 increased by 9.4 percentage point to reach 57.4%, since 2017 and 17.0% of men aged 15-49 years are now classified as obese, with biggest increase in age group 20-29. The prevalence of obesity was higher among men in the above-average and affluent groups (20.0% and 20.6%) compared to men aged 15-49 living in the average and below-average income groups (10.8% and 13.1%).
Conclusion: In Mongolia, one in two men age between 15-49 years were overweight and obese. The prevalence of overweight and obesity has increase age between 30-49 years compared with other groups.

Intrauterine devices (IUDs) are often considered a form of contraception by women of reproductive age because of their reversible, effective, safe, and convenient nature. However, its complications include bleeding, infection, displacement, and uterine perforation. Effective contraception can minimize the risk of unintended pregnancy, particularly for women who have additional health risks associated with unintended pregnancy. Intrauterine device (IUD) is considered to be a highly effective and reversible method of contraception (long-acting reversible contraceptives) that is suitable for most women, highly effective, affordable, and requires minimum patient compliance [1]. Despite being infrequent, perforation constitutes a significant complication associated with IUD insertion, with an estimated incidence of 0.8–2.2 per 1,000 insertions [2, 3]. Ultrasound is the preferred diagnostic modality in cases where partial embedding of the IUD is suspected. However, when the IUD extends near or beyond the uterine serosa, radiologists can more confidently diagnose embedding [4]. The patient is a 44-year-old woman with four children. She gave birth for the first time in 1997. A contraceptive device was inserted in 1999, and another was placed four months after her 2009 delivery. She does not recall the date when she had the latter device removed and has no record of having seen it. This case represents a rare instance of secondary bladder stone formation resulting from migration of an intrauterine device (T-shaped IUD) into the bladder. Rapid diagnostic methods, including ultrasonography, CT, and cystoscopy, along with endoscopic surgical intervention, proved to be the most effective approach for both diagnosis and treatment.

Background: Tick-borne encephalitis is human viral infection involving the nervous system and transmitted by the bite of infected tick. The TBE Virus is distributed in different geographical areas by three widespread subtypes of the virus: The Far East, Europe, and Siberia. The Far East type has a mortality rate was 30-35%, the European type has a mortality rate of 2.2%, and the Siberian type has a mortality rate of 6-8% (A.G. Pletnev, 1998) [2].
In recent years, human cases of tick-borne infections have been reported in 19 European countries and four Asian countries (Mongolia, China, Japan, and South Korea) [3].
Human cases of tick-borne encephalitis, tick-borne rickettsiosis, and tick-borne borreliosis have been registered in Mongolia since 2005. Deaths have been reported year by year [5].
During 2005 to 2021, tick-borne rickettsiosis (71.6%), tick-borne encephalitis (17.3%) and tick-borne borreliosis (52.9%) were confirmed by epidemiological, clinical and laboratory tests at the NCZD.
Tick-borne encephalitis was registered in 63 soums of 15 provinces and 9 districts of the capital city, of which 90% were infected with tick bites in Selenge and Bulgan provinces. The average mortality rate is 4.9% (14), of which 28.6% in Bulgan province and 2.7% in Selenge province.
Tick-borne encephalitis is the leading cause of death in Bugat soum of Bulgan province and more infected men about 40 years of age [7]. Purpose : Collect ticks from selected soums of the provinces, identify tick species, species composition, distribution, tick densities, pathogens of tick-borne diseases, conduct population surveys to assess the risk of tick-borne infections, and identify tick-borne infections. Material and Method: Ticks were collected by flag from birch trees in birch forests and meadows with biotope and overgrown berries, determined morphological analyze and molecular biological investigation for detecting tickborne pathogens.
Questionnaires were collected from selected soum residents according to a specially designed randomized epidemiological and clinical survey card, collected information and forms were submitted to soum hospitals with a history of tick bites (according to clinical criteria). Serological tests were performed to detect IgG-specific antibodies to the collected serum mites. Result and conclusion Collected 121 ticks (120 I. persulcatus and 1 D. nuttalli) and not wound egg, larvae, nymphs. By molecular biological investigation detected 3.5% of I.persulcatus from Khutag-Undur soum of Bulgan province, 3.5% of anaplasmosis, and 14.1% of I.persulcatus mites from Bugat soum. 1.5% borreliosis, 3.1% anaplasmosis.
Detected DNA of 100% tick-borne rickettsiosis from D.nutalli ticks and determined circulation of infection among tick in Bugat and Khutag-Undur soums of Bulgan province.
247 people were surveyed, 56 blood serum from cases. Detected Q fever, erysipelas, and anaplasmosis, tick-borne borreliosis 3 (5.4%), tick-borne rickettsiosis 26 (46.4%), Japanese encephalitis 3 (5.4%), tick-borne encephalitis tick-borne rickettsiosis 6 (13.0%), tick-borne rickettsiosis tick-borne borreliosis 1 (1.8%), tick’s rickettsiosis Japanese encephalitis 1 (1.8%), tick-borne encephalitis tick-borne borreliosis 1 (1.8%).
By investigation, vaccination (88%) and wearing long-sleeved shirts and pants (81%) were the most effective ways to prevent tick bites (81%) [15]. According to our research, the percent of population knowledge in Bulgan province was insufficient (40.9%) which there is a lack of information, training and advertisement among the population in the province.

Introduction: The introduction of minimally invasive surgery has revolutionized multiple disciplines of surgical practice. Objectives: This meta-analysis of matched case control studies aimed to compare the perioperative outcomes of video-assisted thoracic surgery (VATS) with open thoracotomy for patients with early-stage non-small cell lung cancer (NSCLC). Methods: We searched from PubMed and Embase electronic database and revealed seven relevant studies. Endpoints included perioperative mortality and morbidity, postoperative complications and duration of hospitalization. Two investigators (L.S and D.N) independently reviewed each retrieved article. The values of RR and 95% CI were estimated. We used the fixed and random-effects models to estimate the size of the treatment benefit. Results: Results indicate that perioperative mortality was similar between VATS and open thoracotomy (RR-0.62(95%CI 0.39-0.98). However, patients who underwent VATS were found to have fewer overall complications (RR-0.68(95%CI 0.59-0.78), and patients who underwent VATS had a significantly shorter length of hospitalization compared with those who underwent open thoracotomy (MD= -2.98(95%CI-4.09:-1.87)). Conclusions The present meta-analysis demonstrated superior perioperative outcomes for patients who underwent VATS, including overall complication rates and duration of hospitalization. Therefore, our study suggests that VATS should be performed widely to treat patients with lung cancer in the future.

Thyroid nodular lesions are the common clinical problem in the world. A variety of tests have been employed to separate benign from malignant thyroid nodules. These tests include isotope scanning and fine needle aspiration cytology (FNAC). Our research was based on the fact that the comparison of FNAC and thyroid isotope scan in thyroid nodule was not researched in Mongolia. Therefore, we want to evaluate the specimen adequacy of FNAC, and compare its result to thyroid isotope scanning in patients with thyroid nodule. The research was conducted on archive materials of FNAC and thyroid isotope scanning of patients with thyroid nodule who were treated in surgical department of The First Central Hospital from 2012 to 2015, and the statistic analyze was done by using SPSS 20 under the auspices of School of Pharmacy and Bio-Medicine,Department of pathology, Mongolian National University of Medical Sciences. We have collected the FNAC of 807 patients, including 34 patients (4.2%) were males and 773 patients (95.8%) were females. FNA cytology results were interpreted as benign in 495 cases (61.3%), follicular lesion of undetermined significance in 31 cases (3.8%), follicular neoplasm in 9 cases (1.1%) suspicious in 17 cases (2.1%), malignant in 3 cases (0.4%), and unsatisfactory in 252 cases (31%). We have got the result of thyroid isotope scanning of 43 (5.32%) patients out of 807 cases. On thyroid scan, 18 patients (41.9%) having cold nodule were labeled as suspicious for malignancy, 25 patients (58.1%) had hot nodule. The FNA diagnosis of 25 patients with a hot nodule following: 1 patient (4%) with neoplasm, 17 patients (68%) with benign results, 6 patients (24%) had non-diagnostic. The FNA diagnosis of 18 patients (41.9%) with cold nodule following: 1 patient (5.5%) with follicular lesion of undetermined significance, 10 patient (55.5%) with benign, 5 patient (27.7%) with non-diagnostic, 2 patient (11.1%) had malignant. The FNAC results were interpreted as benign in 495 cases (61.3%), malignant in 3 cases (0.4%), and unsatisfactory in 252 cases (31%). Two patients out of 18 patients with cold nodule diagnosed as malignancy by FNAC. The sensitivity and specificity of thyroid isotope scanning was 96% and 16.6%, respectively.

Introduction: A considerable proportionof adult living donor liver transplantation(LDLT) recipients experience biliarycomplication (BC), but there are few reportsregarding BC based on long-term studies ofa large LDLT population.Methods: The present study examinedBC incidence, from 16 adult and pediatricpatients (14 right liver and 2 left liver graft )between 2011 and 2016 First Central Hospitalof Mongolia.Results: The mean follow-up period was36±1 months. First Central Hospital has DDanastmosis (n=22) double DD (n=2) singlehepaticojejunostomy (n=3). There 3 caseshave biliary stricture after operation. One ofthe 3 cases has biliary laek 2 months laterafter the operation.Conclusion: Close surveillance for BCappears necessary for at least the first 3 yrafter LDLT. In terms of anastomotic stenosisrisk, HJ appears a better choice than DD forright liver grafts involving ducts less than 4mm in diameter.

mmon clinical scenario [1]. The prevalenceof thyroid nodules is ~18-40% in Chineseadults [2]; however, only 5-10 percent of allthyroid nodules are malignant. Although withthe development of the ultrasound technique,several ultrasonographic characteristics havebeen associated with thyroid malignancy[3], individual ultrasound features arenot accurate predictors of thyroid cancer.Thyroid fine-needle aspiration [FNA] hasbeen recommended by various organizationsfor the more precise preoperative diagnosisof thyroid nodules [4]. Non-diagnostic rateof FNA comparison and estimate betweenthe other studiesMaterials and Мethods: We performedover 100 FNA using one pass of the 21-Gneedle attached to a 10 ml syringe withoutlocal anesthesia in 2015. All the FNAswere performed without the guidance ofultrasound. Recent study 100 cases of themwere not selected for a specific method.Results: In total there were 100 patientsrecruited in the study with a mean ageof 45.94±13.13 years and 83.0% femalepatients.The Non-diagnostic rate was comparedbetween groups with different needlesizes and methods. In the 22 G group,non-aspiration showed a decreased NDrate as compared to aspiration [44.21 vs.76.76%, P<0.001;]. In the non-aspirationgroup, a lower ND rate was revealed in the25-G needle group compared to the 22-Gneedle group [34.97 vs. 44.21%, P=0.032;].Notably, the ND rate in the 25 G group wassignificantly lower than in the all 22 G group[34.97 vs. 58.13%, P<0.001;]. In the 21 Ggroups, aspiration showed a decreased NDrate as compared to aspiration [44.21 vs.76.76%, P<0.001;]. 21G aspiration groupshowed decrease twofold ND rate ascompared 22G aspiration group [31.63 vs.76.76%, P<0.001;]Conclusion: There have been studiesusing various needle types [regular needle,needle with a stylet or spinal needle [5]and different needle sizes from [21 G to27 G] with or without aspiration duringthe procedure. Numerous factors influencethe diagnostic rate in thyroid FNA, amongwhich the nodule component is an extremelyimportant factor [6]. In general, the morecystic the percentage of each nodule, thehigher the rate of non-diagnostic, with the lowest ND rate in the solid nodule using a25-G needle at 26.77% and the highest inthe cystic nodule using 22 G aspiration at85.19%. A similar trend was found in eachgroup with lowest rate of ND in the 25 Gnon-aspiration group and highest in the 22G aspiration group.

Introduction: Biliary Atresia is a fibroobliterativedisorder of the intra andextrahepatic bile ducts in infancy, which isgoing progressively cholestatic liver disease.The failed Kasaiportoenterostomy requiresliver transplantation. The goal of this studyis to show the outcome of Kasai operation,recent improvement and correlation the datato overseas.Methods and Materials: This study wasconducted in the department of generalsurgery of National Center for Maternal andChild Health of Mongolia between 2010 and2016 on a total of 66 infancies with biliaryatresia.Results: Patient diagnosed with biliaryatresia, which performed Kasai operationwithin first 2 months the outcome is verygood early and late post-operation period.There were 3 patients with 10 year survival, 4patients with 5-10 year and 28 patients with5 year survival after Kasai operation. The mostcomport age for liver transplantation is 1 yearlater after Kasai operation in Mongolia. Livertransplantation programme is necessary forMongolian pediatric surgery, and we thoughtour team was assembled.Conclusion: The children with biliary atresiaperform the Kasai operation within 2 monthsthe outcome is very good. Children with biliaryatresia often experience long wait times fortransplant unless exception points are grantedto reflect severity of disease.In Mongolia livertransplantation done in 2 child.