assessment of different types of mediastinal tumors removed by surgery at taleghani hospital, kermanshah, (2002-2005)

background & objectives: with regard to the mediastinum importance as a central region of thorax and its physiologic traffic of vital structures,the knowledge of mediastinal masses is necessary. this survey was conducted to determine the prevalence of different kinds of mediastinal tumors in patients who underwent surgical procedures at taleghani hospital between 2002 and 2006. methods & materials: this is a descriptive sectional study that was done on the patients files and we used an information form containing variable factors such as kind of mass, place of mass, age, sex, metastasis, clinical signs. after gathering of information, data was analyzed by statistical soft ware. results: among 318 nontraumatic thoracotomies performed in this period, 89 cases were mediastinal masses and most frequent masses were thymic (25.8%) and lymphoma (15.7%).  anterior mediastinum was the most common site affected 66.9% of patients. the average age was 28.2 years and 42% of patients were female. the most significant clinical signs were: weight loss (60.5%), cough (42%), dyspnea (42 %), and chest pain (39.5 %).  metastasis occurred in 33.3% of patients and the most frequent sites were lung and pleural. the frequency of myasthenia gravis in thymoma was 73.7%.  patients with myasthenia gravies with normal thymus and thymectomy were excluded from the study. conclusion: there was little difference between our statistical results and other studies (mass types frequencies and mediastinal compartments most involved by each type of this masses). the only exception was the high prevalence of tuberculosis lymphadenopathy in our study. knowing of common location of mediastinal masses prevents unnecessary aggressive surgical procedures because masses like tuberculosis lymphadenopathy and lymphoma only needs tissue diagnosis and the definite treatments for such diseases are antibiotic and chemoradiation respectively.