Fig. 2

Imaging of preoperative and postoperative operation area. A The space between retrosternal and thymic tumor and fat (Line 1), the space between the thymic tumor and fat outside the pericardium (Line 2), and lift the thymus tissue to separate the thymus along the direction of the innominate vein (Line 3). B Angle of view after parasternal thymic tumor and fat resection (Line 1), angle of view after resection of the thymic tumor and fat outside the pericardium (Line 2), and angle of view after resection of the thymic tumor and fat near the innominate vein (Line 3)