IntroductionCavernous hemangioma in the thymus is a rare presentation in mediastinal hemangiomas. The diagnosis is difficult to make promptly because both invasive and noninvasive examinations usually fail to distinguish it from other tumors of the mediastinum. Their clinical presentations depends on their size and their involvement with adjacent mediastinal structures.Case presentationWe treated a 52-year-old man with thymic cavernous hemangioma that was incidentally detected by chest radiography during a routine health check, and had been misdiagnosed as thymoma before the operation. The tumor was completely resected by thymectomy via video-assisted thoracic surgery. The pathological tissue was diagnosed as a cavernous hemangioma, and no phlebolith was observed in the center.ConclusionsWe reported this case of thymic cavernous hemangioma for its extremely rare occurrence in the thymus. The preoperative diagnosis remains a challenge both clinically and radiologically. It is still difficult to distinguish this tumor from other tumors in the thymus. Furthermore, biopsies might not result in a definitive diagnosis. Finally, surgical resection provides material for histopathologic diagnosis. To facilitate the preoperative diagnosis of such a rare tumor, more cases will need to be reported.