Abstract:

Objective　To discuss the value of CT prediction for staging and invasion of thymoma. Methods　CT characteristics of 79 patients of thymoma established by surgery and pathology were reviewed retrospectively. The total of 79 patients divided into two groups: group A includes stageⅠandⅡ, accounting for 44 cases;  groups B contains stage Ⅲ+Ⅳ, accounting for 35 cases. Distribution, major axis, morphologic characteristics, density and calcification were analyzed. Correlation between CT characteristics and Masaola-Koga was also analyzed.　Results　Major axis, morphologic characteristics, density and calcification were of significant differences among different grades of Masaoka-Koga classification and the P values are 0.000, 0.000, 0.001, and 0.002, (P<0.05), respectively. There were no significant difference between the two groups of tumor distribution (P=0.418). Positive predictive value of CT characteristics on mediastinal fat, mediastinal pleura, pericardium, adjacent pulmonary parenchyma, as well as blood vessles were 83.67%, 76.92%, 71.43%,66.67%, 80%, respectively, and the negative predictive value were 80%, 96.22%, 95.55%, 94.83%, 97.3%, respectively.　Conclusion　CT imaging can differentiate different stages of thymoma,providing help in evaluating the need of neoadjuvant therapy or not before surgery, therefore, improving the prognosis.

Key words: Thymoma, Computed tomography, Staging, Invasion