Background: Non-small cell lung cancer (NSCLC) accounts for the majority of lung cancer cases and remains one of the leading causes of cancer-related mortality worldwide. Advances in molecular oncology have shown that mutations in the epidermal growth factor receptor (EGFR) gene play a crucial role in diagnosis and in guiding targeted therapy with tyrosine kinase inhibitors (TKIs). However, the detection of EGFR mutations is influenced by specimen type and quality, and differences may exist between bronchoscopic and surgical samples. In Mongolia, studies addressing this issue remain limited. Aim: To evaluate the feasibility of detecting EGFR gene mutations in bronchoscopic and surgically obtained tissue samples from patients with non-small cell lung cancer (NSCLC). Materials and Methods: This prospective comparative study included 35 formalin-fixed, paraffin-embedded (FFPE) tissue samples, of which 19 were bronchoscopic and 16 were surgical specimens. Tumor cell content was assessed histologically, and genomic DNA was extracted from each sample. EGFR mutation analysis was performed using the cobas® EGFR Mutation Test v2 with real-time PCR. Statistical analysis was conducted using SPSS version 26.0, and differences between groups were evaluated using Fisher’s exact test. Results: The mean age of the participants was 64.5±10.5 years; 74% were male and 26% were female. Significant differences in tumor cell content and DNA yield were observed between specimen types. Bronchoscopic samples showed a mean tumor cell content of 34%, with sufficient DNA yield in 73.6% of cases, whereas surgical specimens demonstrated a mean tumor cell content of 93%, with adequate DNA yield in all cases. EGFR mutations were detected in 31.3% of surgical specimens (including exon 19 deletion, L858R, and T790M mutations). In bronchoscopic samples, insufficient DNA yield in some cases precluded PCR analysis, thereby limiting mutation detection. A statistically significant difference in EGFR mutation detection rates was observed between the two groups (p=0.045). Conclusions 1. Bronchoscopic samples demonstrated lower tumor cell content and DNA yield, which may limit their suitability for molecular analysis in some cases. 2. Compared to bronchoscopic samples, surgically obtained specimens provided higher-quality tissue and demonstrated a greater feasibility for EGFR mutation detection.

Background: Hidradenitis suppurativa (HS) is a chronic, recurrent inflammatory disorder of the hair follicle that predominantly affects areas rich in apocrine sweat glands, such as the axillae and groin. Clinically, it is characterized by painful nodules, abscess formation, sinus tract development, and scarring. Diagnosis is primarily based on clinical findings; however, due to limited awareness of the disease, it is often diagnosed at a late stage. Misdiagnosis and inappropriate management are common, leading to chronic disease progression. Consequently, HS significantly impairs quality of life through reduced work capacity, psychological distress, and social isolation. Disease severity is commonly assessed using the Hurley staging system and the Sartorius scoring system. We present a rare case of hidradenitis suppurativa encountered in dermatological practice. Case presentation A 35-year-old male patient (initials L.B.) presented with recurrent, painful lesions in both axillary regions associated with purulent discharge. The condition had persisted over a prolonged period with repeated exacerbations. The patient had attempted self-treatment at home without improvement and was subsequently admitted to the Department of Dermatology at the National Center for Dermatology with a diagnosis of DS: L73.2 (hidradenitis suppurativa). The patient was treated with systemic antibiotics (doxycycline and cefazolin), retinoids, supportive therapy, and topical treatment. In addition, intralesional triamcinolone injections were administered into active nodules, which proved effective in rapidly reducing inflammation, pain, and purulent discharge.

Background: A rare angioproliferative condition of the larynx, Kaposhi sarcoma typically affects the skin. Immunosuppressive treatment following organ transplantation and human immunodeficiency virus infection are the causes. Every type of Kaposi sarcoma has human herpesvirus-8. Laryngeal kaposi sarcoma is uncommon in immunocompromised patients; since its initial identification in 1965, 18 cases have been documented globally. A CO2 laser-assisted laryngeal microsurgery is performed through the mouth cavity to remove tumor when kaposi sarcoma of the larynx obstructs the airway. Case report: A 77-year-old woman complained of hoarseness, dry mouth, odynophagia, and dysphagia three months prior when she arrived at the Mongolian-Japan Hospital. Two years ago, she acquired hard, sensitive lumps that were palpable on her right arm, left ankle, and right thigh. At that time, she was diagnosed with Kaposiform hemangiodermatitis and treated at the National Center for Dermatology. HIV test results were negative. Immunohistochemistry: CD31 +/-, CD34 /+/. Using flexible nasopharyngeal endoscopy to get the diagnosis: There was a mass that was about 1.5–2–5 cm in diameter, bluish in color, smooth and movable, and spongy and vascular on the larynx, on the nasopharynx, behind the palatine tonsills, and supraglottic. Surgery: Through the use of Kleinsasser laryngoscopy and a 0-degree endoscope, pathological tissues were extracted under general anesthesia using a laryngeal microsurgical instrument and a laparoscopic bipolar coagulator. The tissues were then sent for histological evaluation, which revealed Kaposi sarcoma, sarcoma grade 1. Results of treatment Pain decreased and quality of life increased following surgery. Upon nasopharyngeal endoscopy, the vocal cord mobility was normal and the surgical incision was clean. Conclusion: Kaposi sarcoma is an extremely uncommon illness. A lower quality of life and further issues can be avoided with an early diagnosis and suitable therapy. It also needs to be continuously monitored because it is a potentially repeatable disease.

Background: Azoospermia is the most severe form of male infertility, affecting approximately 1% of male population and 10–15% of infertile men. In azoospermia cases, sperm retrieval from the testis or epididymis through surgical procedures is used for assisted reproductive treatments. When no sperm is retrieved, recent approaches in medicine suggest using immunohistochemical methods to evaluate spermatogenesis in testicular tissue and plan further treatments. Aim: To evaluate spermatogenesis in testicular tissue of azoospermic patients using immunohistochemistry and compare the findings with the clinical outcomes of sperm retrieval procedures. Materials and Methods: This study included 71 azoospermic men who underwent micro-TESE procedures at the IVF center (RMC) between 2019 and 2023. The excised testicular tissues were fixed, processed histologically, and evaluated using Johnson’s score. The presence of spermatozoa in seminiferous tubules was detected by immunohistochemical and immunofluorescence staining, using markers such as TEX101 and LDHC. Results: Johnson’s score was categorized into three groups: poor, moderate, and good spermatogenesis. These were statistically compared with hormonal levels and surgical sperm retrieval outcomes. There were significant differences in Johnson’s scores and serum FSH and LH levels among the three groups (p < 0.005). TEX101 and LDHC proteins were strongly expressed in the good group, weakly in the moderate group, and absent in the poor group. The success rate of sperm retrieval was 100% (17/17) in the good group, 96.29% (26/27) in the moderate group, and only 29.62% (8/27) in the poor group. Conclusion Histological evaluation of spermatogenesis in azoospermic patients can help predict the outcome of surgical sperm retrieval, indicating its clinical value in treatment planning.

Background: Gastroesophageal reflux disease (GERD) composes up to 28% of the esophageal disorders, and diagnosis of GERD is associated with a 10-15% of risk of Barrett’s esophagus, change of normal squamous epithelium of the distal esophagus to a columnar-lined intestinal metaplasia. It is reported that gastrointestinal (GI) disorders are the second out of five leading diseases in ambulatory diagnosed diseases and in 2022, esophageal adenocarcinoma is ranked in the fourth of the 10 most prevalent cancers among Mongolian population. When the Barrett’s esophagus changes shift to dysplasia, risk of esophageal adenocarcinoma development rises 30-125 folds and every year, 0.8% of population with dysplastic changes suffer from esophageal carcinoma. Although specific staining methods for histochemical analysis has been introduced into pathological laboratories detecting protein, fat, nucleic acid and enzymes that contained in cells, there isn’t study has been conducted to investigate the diagnostic specificity of Alcian blue and PAS staining method among population with Barrett’s esophagus. Aim: We aimed to make a differential diagnosis with basic and histochemical staining method in esophageal biopsies from Second Central Hospital of Mongolia (SCHM) and Mongolia-Japan hospital of MNUMS. Results: A total of 589 biopsies were collected from the SCHM and Mongolia-Japan Hospital of MNUMS and hematoxylin and eosin-stained results were Barret’s esophagus (43 biopsies or 7.3%), followed by Squamous cell carcinoma (46 or 7.8%), GERD (60 or 10.2%), hyperplastic polyp (92 or 15.6%), chronic erosive lesions (242 or 41%), polyp (94 or 15.9%), adenocarcinoma (12 or 2%), respectively. We have re-examined 43 cases with Barrett’s esophagus staining with Alcian blue and PAS and as a result, acidic mucin will be blue, neutral mucin will be purple, mixed mucin will be blue-purple and nucleus will be stained blue, respectively. Immunohistochemical re-staining of 43 biopsies with BE, Alcian blue were 87.8% and PAS were 97.4%. Conclusion Barrett›s esophagus, esophageal papilloma and hyperplastic polyps are comprising most of the esophageal precancerous disorders, and 9.8% of esophageal carcinoma was diagnosed. Histochemical re-staining of esophageal intestinal metaplastic changes is significantly beneficial to confirmation of the diagnosis.

Background: Globally, an estimated 13% of adolescents aged 10–19 are affected by mental disorders. As of 2020, the number of children under the age of 19 in Mongolia was reported to be 1,289,587, reflecting a 0.9% increase compared to 2015. A 2013 study on adolescents found that 60.5% were categorized as mentally healthy, 30.5% exhibited emotional and behavioral difficulties, and 9% were diagnosed with a mental disorder. A study conducted in Govi-Altai Province between 2018 and 2019 reported that 58.6% of adolescents were classified as healthy, 36.1% experienced psychological difficulties, and 5.2% were diagnosed with a mental disorder. Internationally, adolescent mental health has been widely assessed using the Strengths and Difficulties Questionnaire (SDQ), with an increasing number of studies employing artificial intelligence-based predictive models. However, in Mongolia, research utilizing artificial intelligence and machine learning for analyzing large-scale mental health data remains limited. This gap underscores the need for the present study. Aim: Machine learning models were compared to determine adolescent emotional and behavioral problems using the SDQ. Materials and Methods: Data was collected from teenagers, teachers, and parents in Govi-Altai Province, and the databases were created for each group. The teenager database was divided into 10 folds by cross-validation, and the models were developed using machine learning methods and evaluated using their performance measures. The results were mainly analyzed using the Bayes model. Results: The teenagers have emotional and behavioral problems due to emotional and peer interactions, but they are at risk of developing disorders due to hyperactivity and behavioral changes. Conclusion Comparing the model performance results with previous studies, Bayesian model accuracy decreased by 0.03, sensitivity decreased by 0.08, and specificity increased by 0.01. Also, the difference between the performance evaluation metrics of the C50 and Bayesian models is very small, between 0.01 and 0.02. This shows that the performance of the Bayesian method is good when the number of attributes in the database increases. Compared to the results of the knowledge generated by the research, the participants are more likely to develop emotional and behavioral disorders due to their peer relationship indicators, such as other children generally not liking them, getting on better with adults, and due to emotional symptoms such as being unhappy and depressed.

Background: Nasal bone fracture is the most common facial bone injury and remains a significant clinical and forensic concern. Although perceived as minor, management can lead to long-term complications such as external nasal deformity, septal perforation, nasal obstruction, and chronic rhinosinusitis. These sequelae compromise quality of life and frequently give rise to medico-legal disputes regarding the assessment of health damage and work capacity. Aim: To characterize nasal bone fractures and septal deformities and to evaluate their correlation with the severity of health damage and loss of work capacity. Materials and Methods: A cross-sectional study was conducted involving 70 patients individuals with acute nasal bone fractures treated at the Department of Otorhinolaryngology, First Central Hospital of Mongolia, and patients with minor injuries assessed at the National Forensic Agency of Mongolia. Data collection included structured questionnaires, physical examination, nasal endoscopy and computed tomography. Nasal bone fractures were classified according to Hwang (2002) and septal deviations were categorized using Mladina’s classification (1987). Statistical analyses were performed to explore associations between fracture type, septal deviation, nasal obstruction and functional impairment. Results: Septal deviation was identified in 60% of patients without fracture and in 40% of those with concurrent fractures. Among 60 cases of blunt nasal trauma, septal deviation showed a statistically significant association with septal fracture (p=0.001). Hwang type II, III, and IV fractures demonstrated the strongest correlation with unilateral or bilateral nasal obstruction (χ²=29.72). Bilateral nasal bone fractures were more frequently associated with septal deviation, while logistic regression analysis revealed an increased risk of impaired work capacity (coefficient 0.237). Conclusion 1. In 40% of the study participants with nasal trauma, nasal bone fractures were accompanied by septal injury, initially classified as mild. 2. These patients underwent surgical treatment; however, when the recovery period extended beyond four weeks a reassessment of health impairment was required. According to the criterion of prolonged disruption of health, the degree of impairment was subsequently reclassified as moderate.

: Background: According to the statistics, Gastrointestinal disorders (GIDs) are the second of the leading five diseases among Mongolians, with an estimated 20% of GIDs by pathological diagnosis in 2022. Additionally, esophageal adenocarcinoma is ranked in the 4^th of the 10 most common cancer. Esophageal adenocarcinoma and its predispositions, and pathological changes are mostly located lower part of esophagus. Barret’s esophagus (BE) is consequences of goblet cell replaces the stratified squamous epithelium due to chronic gastroesophageal reflux disease. If BE transfers to the dysplasia, its probability of carcinogenesis is 30-125 times higher, and 0.8% of dysplastic patients with BE diagnosed with esophageal adenocarcinoma. Pathologists play a critical role in confirming the diagnosis of BE and BE-associated dysplasia. Goblet cells are almost always identifiable on routine hematoxylin and eosin-stained sections with Alcian blue (at pH 2.5). Purpose: To diagnose the esophageal biopsies via pathological immunohistochemical assay. Methods and materials: We investigated 130 biopsies in 2017-2019 years from NFCH, and 254 biopsies in SSCH. Result A total of 384 biopsies were collected from both national central hospitals and hematoxylin and eosin-stained results were Barret’s esophagus (50 biopsy or 13%), followed by dysplasia (66 or 17%), GERD (55 or 14%), squamous cell carcinoma (49 or 13%), chronic erosive lesions (41 or 11%), chronic esophagitis (40 or 10%), polyp (19 or 5%), adenocarcinoma (15 or 4%), acute esophageal erosion (5 or 1%), hyperplastic polyp (36 or 9%), and were others (8 or 2%), respectively.
As a result of immunohistochemical re staining of 50 biopsies with BE, Alcian blue were 87,8% and PAS were 97,4%.

Introduction: Hepatocellular carcinoma incidence and mortality per 100,000 population in Mongolia is the highest in the world. The individual’s genetic factors and new genetic changes are considered an important effect on the origin and development cancer. We aimed to investigate whether p53R72P polymorphisms were associated with the risk of hepatocellular carcinoma in Mongolian patients. Material and Method: p53R72P polymorphisms were evaluated in 80 controls and 38 HCC cases using a PCRrestriction fragment length polymorphism assay. Results: The mean age was 58.5±13.6 years in the case group and 63.2±8.1 years in the control group. Hepatocellular carcinoma is most common in 50-59 (n=14, 36.8%) and 60-69 (n=14, 36.8%) ages. Of the HCC group, 4 (10.8%) were diagnosed with tumor at stage II, 23 (62.2%) at stage III, and 11 (27%) at stage IV.
The results revealed that the heterozygous (Arg/Pro (PR)) genotype of p53R72P increased statistically significant the risk of hepatocellular carcinoma (OR=4.222, 95% CI 1.669-10.684) compared to the wildtype (R/R) genotype. (p=0.002). Moreover, the homozygous (Pro/Pro (P/P)) genotype of p53R72P increased the risk of carcinoma (OR=1.333, 95% CI 0.414-4.299) but not statistically significant. (p=0.63). Heterozygous (Arg/Pro (PR)) genotype of p53R72P in the tumor tissue was associated with a statistically significant (OR=3.3, 95% CI 1.274-8.57) increase in the risk of HCC (p=0.014). Pro/Pro (PP) genotype increased the risk of the carcinoma by 2.4 times (OR=2.44, 95% CI 0.865-6.908), but it was not significant. (p=0.092). Pro/Pro (PP) genotype of p53R72P in the tumor tissue compared to normal tissue of a case group increased the risk of cancer by 1.8 times (OR=1.833, 95% CI 0.472- 7.126), which was not statistically significant (p=0.382). Conclusion Taken together, Heterozygous (Arg/Pro (PR)) genotype of p53R72P increases the risk of hepatocellular carcinoma in Mongolians. Further studies with larger populations are needed to confirm these results.

Background: Lung cancer is the leading cause of cancer death in both men and women. In the past decade, histopathological classification of lung cancer has become increasingly important in selecting the appropriate treatment. Methods: All cases of lung cancer diagnosed pathologically in the last 2.5-year period were retrospectively identified at National Cancer Center and performed by descriptive case series design. Results: The average age of our participants was 62, of which 82.2% were men. A total of 214 cases of lung cancer were reported, including 142 (66.4%) squamous cell carcinoma (SCC), 34 (16%) adenocarcinoma (AC), 4 (1.7%) NSCLC, 29 (13.6%) small cell carcinoma (SmCC) and 5 (2.3%) cases of other/unspecified type. Based on only morphology, initially 32 (17.7%) cases of NSCLC were diagnosed, whereas after immunohistochemistry (TTF-1 or NAPA positive/p63 negative, and vice versa) staining, this category reduced to 2.2%. Conclusions Among both males and females, SCC which is highly related to smoking was the most common histologic type of lung cancer. Our results showed that an approach of using only a two-antibody panel (p63 and TTF-1) might help in the reduction of diagnostic category of NSCLC-NOS significantly.