[Primary anterior mediastinal huge lipoma: report of a case].

We report a case of anterior mediastinal lipoma. A 71-year-old female was admitted for cough. A fat density tumor from anterior mediastinum to left thoracic cavity was found by chest X-ray, chest computed tomography (CT) and magnetic resonance imaging (MRI). Defect of left dorsal diaphragm was suspected and there was a possibility that the tumor was connected to retroperitoneum. Under the preoperative diagnosis of a benign huge mediastinal lipoma, we conducted an operation. At 1st, we observed by thoracoscopy and made sure that the mass was primary anterior mediastinal tumor and not connected to retroperitoneum. Through the median sternotomy, we completely resected the tumor with thymus. The tumor showed 27 cm in diameter, and histopathological diagnosis of the tumor was benign lipoma. Lipoma of the mediastinum is very rare and about 0.3% of all mediastinal tumors. It is sometimes difficult to distinguish huge lipoma from liposarcoma only by clinical examinations such as CT scan or MRI. We evaluated the condition of the tumor by thoracoscopic observation, and the tumor was safely and completely resected by median sternotomy.