Some signs suggest the maglinant tumor diagnosis: large tumor size, irregular (60%) or lobulated contours (26.7%), Heterogeneous attenuation (86.7%), Heterogeneous enhancement (86.7%), calcification in tumor (33.3%), necrosis in tumor (66.7%), pleural effusion (53.3%), pericardial effusion (6.7%), invasion signs (Mediastinal fat invasion (80%), mediastinal lymphadenopathy (60%), metastasis (33.3%), great vessel invasion (26.7%)). Conclusion: Evaluation of benign and malignant tumor charac-teristics before the surgery is important, helping with treatment and prognosis.