Background: Histopathological examination of skin tissue plays an important role in the diagnosis of dermatological diseases; however, data on surgically excised skin specimens remain limited in Mongolia. Aim: To classify benign and malignant tumors based on histopathological findings of surgically excised skin tissue specimens, determine surgical margin status, and evaluate the age and sex distribution of these conditions. Materials and Methods: This retrospective observational study was conducted using data on surgically excised tissue specimens collected in the outpatient department of the National Dermatology Center between January 2023 and March 2026. A total of 361 patients were identified. Four cases with indeterminate histopathological diagnoses were excluded, leaving 357 patients for final analysis. Data on age, sex, diagnosis, and surgical margin status were collected and analyzed on Microsoft Excel programm. Histopathological diagnoses were classified as benign or malignant tumors. Associations between categorical variables were assessed using the chi-square test, with statistical significance set at p < 0.05. Results: Among 357 patients, 135 (37.8%) were male and 222 (62.2%) were female, with a mean age of 41.8 years. The 20–39-year age group accounted for the largest proportion of cases (39.5%). Histopathological examination showed that 326 cases (91.32%) were benign and 31 cases (8.68%) were malignant. Among benign tumors, melanocytic nevus was the most common diagnosis, while basal cell carcinoma was the most common malignant tumor. The frequency of malignant tumors increased significantly with age (p < 0.001). Patients aged ≥60 years had significantly higher odds of malignancy compared with younger patients (OR = 8.19, 95% CI: 3.79–17.69). Malignant lesions were significantly more likely to have positive (involved) surgical margins than benign lesions. Conclusion Most surgically excised skin tissue specimens were benign; however, the likelihood of malignancy increased significantly with age. Surgical margin assessment is clinically important for improving prognosis, reducing the risk of recurrence, and guiding treatment management.

Sleep and wakefulness are physiological processes in our lives that are regulated by circadian rhythms. The level of melatonin, the "sleep hormone", increases with the onset of darkness, and its production slows down in the morning. Exposure to artificial light at night disrupts our circadian rhythm and the processes it controls. Shift work is when an individual works from 9 am to 5 pm. But the night shift refers to the time when a group of workers who work at night in factories and enterprises work in the evening or at night, especially from 4 p.m. to 8 a.m. according to a regular schedule. One in five people in industrialized countries work night shifts, and studies in America and Europe show that between 15 and 30% of adult workers have some form of shift work. Between 10% and 30% of shift workers meet the diagnosis of shift work disorder (SWD). 5-10% of shift workers experience severe shift insomnia and sleepiness. At least ¾ of shift workers suffer from insomnia. Excessive sleepiness usually occurs during shifts (mainly at night) and is associated with impaired cognitive ability due to the need for sleep and reduced alertness, and decreased alertness reduces performance. Job performance is influenced by many workplace environmental factors, including workload, coworker relationships, stress levels, and extended hours. A nurse specialist provides nursing care by monitoring and evaluating 24 hours a day, and by working night shifts, the circadian system of sleep is disturbed, causing sleep problems and insomnia. When examining how night shift work affects nurses' ability to concentrate, the decline in concentration (33.3%) was twice as high as that of day shift nurses (16.7%). found that shift nurses who worked the night shift had higher rates of insomnia and chronic fatigue compared to nurses who stopped working the night shift. Lack of sleep manifests as a decline in cognitive functions such as attention, decision making, and reaction time. These cognitive and functional declines can negatively affect quality of life and lead to impaired job performance. An Australian study by Winwood et al found that fatigue associated with night shifts increases the risk of human error and injury, and negatively affects the quality of patient care. Lack of sleep significantly affects nurses' alertness, concentration, and job performance. This review article discusses the relation between shift work-related sleep and job performance based on international research findings.