Efficacy of computed tomography features in predicting stage III thymic tumors

Accurate assessment of the invasion of intrathoracic structures by stage III thymic tumors assists their appropriate management. The present study aimed to evaluate the efficacy of computed tomography (CT) features for the prediction of stage III thymoma invasion. The pre-operative CT images of 66 patients with confirmed stage III thymic tumors were reviewed retrospectively. The CT features of invasion into the mediastinal pleura, lungs, pericardium and great vessels were analyzed, and their sensitivity, specificity, positive predictive value (PPV), negative predictive value and accuracy were calculated. For mediastinal pleural and pericardial invasion, an absence of space between the tumor and the mediastinal pleura/pericardium with mediastinal pleural/pericardial thickening and pleural/pericardial effusion exhibited a specificity and PPV of 100%, respectively. For lung invasion, a multi-lobular tumor convex to the lung with adjacent lung abnormalities exhibited a specificity and PPV of 91.2 and 81.3%, respectively. For vessel invasion, the specificity and PPV were each 100% for tumors abutting ≥50% of the vessel circumference, and for tumor oppression, deformation and occlusion of the vessel. In conclusion, recognition of the appropriate CT features can serve as a guide to invasion by stage III thymic tumors, and can facilitate the selection of appropriate pre-operative treatment.