The valve of CT in diagnosing the invasive and non-invasive thymoma

Objective: To Study CT features of thymoma and its value in differentiating the invasive from non-invasive thymoma. Methods: CT findings of 17 cases with thymoma (11 non-invasive and 6 invasive) confirmed by surgery and pathology were analyzed retrospectively. Results: 11 cases were non-invasive thymoma. On CT, the tumors were round or oval in 6 cases, lobulate in 4 cases, and irregular in 1 case. The lesions showed homogeneous density and mild enhancement in 9 cases. 10 of them showed complete capsules without invasion. The mass-cardiovascular interface was: convex type in 5 cases, flat type in 3 cases and concave type in 2 cases. 6 cases were invasive thymoma, tumors were irregular and heterogeneous in 5 cases. Significant and inhomogeneous enhancement on post contrast CT was found. Conclusion: The CT features of thymoma was specific, and CT is of great value in differentiating the invasive from non-invasive thymoma. (authors)