We report a patient with an extra-ordinarily huge thymoma weighing 1,9
30 g and measuring 21 x 20 x 15 cm that filled almost the entire hemit
horax. The tumor was successfully removed and the patient made a good
recovery. Despite of its large size, the tumor was benign both clinica
lly and histologically, and the pathological diagnosis was epithelial
thymoma of non-invasive type. The perioperative changes of this patien
t's lung function are discussed in detail.