Chest wall lipoma mimicking well-differentiated liposarcoma

A 63-year-old man was referred to our hospital due to a growing chest wall tumor. Computed tomography (CT) showed a well-defined and well-circumscribed tumor, and magnetic resonance imaging showed a high signal intensity in both T1- and T2-weighted images and a low signal intensity with fat suppression. CT-guided biopsy showed an atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS), and surgery was performed. The tumor did not infiltrate the chest wall but adhered to the lung; we resected the tumor and a part of the lung without additional resection of the chest wall. The pathological diagnosis was chest wall lipoma with inflammation, and the absence of invasion to the lung was confirmed. The patient was doing well and free from recurrence at 14 months after surgery. Surgeons should recognize that it is difficult to distinguish ALT/WDLPS from lipoma based on pre-operative findings of clinical imaging. Marginal resection may be a reasonable operative procedure for chest wall lipoma or ALT/WDLPS, and adjuvant treatment might be considered if needed.