Background and Objective: One of the important steps in continuing the treatment of patients with mediastinal masses is the definitive diagnosis using tissue sampling of the lesion within the mediastinum. One of the methods used for this purpose is mediastinoscopy. In this regard, this study aimed to determine the results of mediastinoscopic surgery in patients with a mediastinal mass. Materials and Methods: This descriptive study evaluated the medical files of all patients who underwent mediastinoscopic surgery in Besat Hospital, Hamadan, Iran, from 2014 to 2019. Results: This study was conducted on 19 patients with a mean age of 50.84 years. The majority of the participants were male (n=11). The mass was located in the anterior mediastinum in most of the patients (n=16), and in three cases, it was in the median mediastinum. Histopathological results showed inflammation (n=4), small cell carcinoma (n=3), lymphoma (n=2), squamous cell carcinoma (n=2), metastasis (n=2), adenocarcinoma (n=1), hydatid cyst (n=1), tuberculosis (n=1), sarcoidosis (n=1), anthracosis (n=1), and nonspecific (n=1) in descending order. Conclusion:In general, there are similarities between the results of this study and those of other studies in terms of age, gender, place of involvement in the mediastinum, and surgical complications. On the other hand, there are differences between this study and other studies regarding the pathology results. It seems that the frequency of malignant masses in our study is higher than that in other studies.

Introduction: Musculoskeletal Disorders)MSDs(are one of the most important factors of occupational injuries and disabilities in workplaces. Back injuries are the most common work-related disorders in different industries. The aim of the present study was ergonomics intervention to reduce these disorders. Methods: This interventional study was conducted on 126 preservation and maintenance workers in a cement company by classification sampling. The Nordic Musculoskeletal Disorders Questionnaire, QEC and ergonomics checkpoints were used to collect data before and after the interventions. The interventional program included practical and easy-to-implement solutions for improving safety, health and work conditions, workers' training, and selective and corrective exercise. Data were analyzed by McNemar's test using SPSS version 22 software. Results: Data analysis showed a significant difference)P-value > 0.001(between the prevalence of disorders during the one week before and after the interventions. The prevalence of disorders for lower back and knee were 62.70% and 60.32%, which were reduced to 46.03% and 43.65 after the intervention, respectively. conclusions: According to QEC method, 83 maintenance workers)65.87%(were at high risks, and the prevalence of lower back and knee pains was high, that applying simple and inexpensive solutions, participatory solutions of ergonomics checkpoints and selective corrective exercise led to a significant reduction in these disorders.