[Diaphragmatic lipoma needed to distinguish from Bochdalek hernia; report of a case].

A 69-year-old woman had been followed up for an abnormal shadow on the left diaphragm at a nearby hospital, which showed gradual increase in size and she was referred to our hospital for treatment. Chest computed tomography(CT) showed a dome-shaped and homogeneous mass with smooth surface on the left diaphragm. CT showed 50×60 mm hypodense mass and partly interrupted diaphragm. Magnetic resonance imaging( MRI) revealed fat signal intensity on both T1 and T2 weighted image and fat suppressed T1 image. Bochdalek hernia or diaphragm lipoma was suggested and surgery was done. Yellowish round tumor on the diaphragm was resected. The omentum was easily separated from the tumor. Histopathological finding revealed the lipoma cell invading into striated muscle of diaphragm, and the tumor was diagnosed as a mature lipoma originated from diaphragm.