Objective To improve the diagnostic accuracy rate of cystic thymoma and cystic teratoma by investigating their imaging features and differential diagnosis.

Methods Retrospectively analyzed the X-ray and CT scanning images of 30 patients, including 12 cases of cystic teratoma and 18 cases of cystic thymoma, which were confirmed via surgery and pathology.

Results All of the tumors were localized in the anterior mediastinum, except in one case wherein the tumor extended into the middle mediastinum.In addition, the majority of masses were biased on one side.The cystic thymoma cases showed obvious leaf and were cystic; several tumors also exhibited small mural nodules.Moreover, the adjacent vascular structures were pushed, the lung tissue was compressed by some lesions, and part of the tumor may be secondary to breast changes, such as pleural effusion.All of the teratoma cases were cystic, although no significant bone and fat components were found in the tumor.The density of cystic teratoma was also heterogeneous but not completely cystic.

Conclusion Cystic thymoma and cystic teratoma exhibited certain pathological and imaging features, and can be accurately diagnosed based on their features and clinical manifestations.