Intrathoracic lipoma of chest wall misdiagnosed as liposarcoma with malignant features based on radiological image and intraoperative findings

Lipomas are common benign tumors, which are usually located in the subcutaneous tissue. It is relatively rare for lipoma to occur in the intrathoracic cavity, and it is clinically difficult to distinguish it from liposarcoma. We present the case of a 72-year-old man with a chest wall tumor preoperatively diagnosed as liposarcoma, with tumor enlargement with radiological image change to heterogenous and 18F-fluorodeoxyglucose positron emission tomography uptake. The tumor was resected along the chest wall, lung and diaphragm because of dense adhesions. The tumor was diagnosed as lipoma with fat necrosis and inflammatory changes.