A huge non-invasive thymoma causing acute dyspnea.

We report a patient with an extra-ordinarily huge thymoma weighing 1,930 g and measuring 21 x 20 x 15 cm that filled almost the entire hemithorax. The tumor was successfully removed and the patient made a good recovery. Despite of its large size, the tumor was benign both clinically and histologically, and the pathological diagnosis was epithelial thymoma of non-invasive type. The perioperative changes of this patient's lung function are discussed in detail.