抄録
A 51-old man was admitted to our hospital because of sudden tarry stool and dizziness. Upper gastrointestinal endoscopy revealed an elevated lesion with erosions located at the posterior wall of upper gastric body. A pulsatile bleeding was seen from the surface of this tumor. On the CT, this tumor had a relation to the muscular layer of the stomach and developed into extra-gastric wall. An operation was performed. On the immunologic examination, since tumor cells were positive for CD34 and c-kit, but negative for α-smooth muscle actin and desmin and S-100 protein, this tumor was diagnosed as a gastrointestinal stromal tumor (GIST) ．
