[A case of a primary gastrointestinal stromal tumor (GIST) found in the greater omentum of a 99-year-old woman].

We report the case of a primary gastrointestinal stromal tumor (GIST) found in the greater omentum of an extremely elderly woman. A 99-year-old woman with a history of heart failure and renal failure presented with dyspnea and disturbance of consciousness. A tumor located between the stomach and spleen had been detected by abdominal computed tomography three years previously. After admission, she received oxygen supplementation and diuretics. However she died of heart failure and disseminated intravascular coagulation on the 31st day of hospitalization. Autopsy was performed on the same day. A large mass measuring 12.5 x 7.0 x 7.5 cm was revealed, originating from the greater omentum. Histopathologically, it was composed of spindle cells with the nuclei showing a focal palisading pattern, however there were no mitoses. Immunohistochemically, the tumor was positive for c-kit. The tumor was diagnosed as a primary GIST of the greater omentum.