Thymoma originating in a giant thymolipoma: a rare intrathoracic lesion

Thymolipoma is a rare, slow-growing, benign tumor that arises from the anterior mediastinum and corresponds to 2% to 9% of all thymic neoplasms. We present the case of a 49-year-old man who had a large heterogeneous mass with areas of soft tissue and fat tissue located on the anterior mediastinum and right hemithorax. After resection, histologic analysis confirmed the diagnosis of a giant thymolipoma containing solid components that corresponded to thymomas B1, B2, and B3. We discuss the occurrence of an atypical variant of thymolipoma containing three types of thymomas inside.