胸主动脉瘤是由于主动脉管壁发生于退行性改变而产生的局部囊性扩张。本病形态像瘤 ,实际病理改变与肿瘤截然不同。本病临床上比较少见 ,往往误诊。我院自 1986年以来共遇到 11例胸主动脉瘤 ,其中 7例误诊为纵隔良性肿瘤 ,1例因胸前有主动脉搏动而明确诊断 ;2例行彩超确诊检查 Thoracic aortic aneurysms are local cystic dilations due to degenerative changes in the wall of the aorta. The disease is like a tumor. The actual pathological changes are very different from those of the tumor. The disease is rare in clinical practice and is often misdiagnosed. A total of 11 cases of thoracic aortic aneurysms have been encountered in our hospital since 1986, of which 7 cases were misdiagnosed as benign mediastinal tumors, 1 case was diagnosed as having aortic beats in the chest, and 2 cases were diagnosed with color Doppler ultrasound.