A case of multicentric gastrointestinal angiosarcoma suffering from se
vere melena is presented. Endoscopical examination revealed two polyps
in the stomach and duodenum. Histological examination showed angiosar
coma. Although a gastroduodenectomy was performed, severe melena conti
nued, and the patient developed respiratory failure and died. At autop
sy, multiple hemorrhagic tumors were present from the duodenum to the
cecum. Histologically the tumors demonstrated vasoformative structure
and were immunohistochemically positive for von Willebrand factor (fac
tor VIII related antigen), CD34, and CD31. Numerous metastases were fo
und in various organs, including the lungs, bones, liver, gall-bladder
, and lymph nodes. The patient had received hemodialysis for 21 years
due to chronic renal failure. Long-term dialysis had been associated w
ith Various malignancies. Multicentric development of angiosarcoma in
the present case may also be related to long-term dialysis.