Disseminated Angiosarcoma With Multifocal Small-Bowel Involvement Presenting as Suspected Small-Bowel Bleeding

Angiosarcoma is a rare, aggressive vascular malignancy, and gastrointestinal involvement is uncommon. We report disseminated angiosarcoma with multifocal small-bowel involvement presenting as suspected small-bowel bleeding, in which small-bowel capsule endoscopy (SBCE) and double-balloon endoscopy (DBE) were diagnostically useful. A man in his 60s presented with recurrent melena and transfusion-dependent anemia. SBCE showed active jejunal bleeding with multiple ulcerative lesions, and antegrade DBE revealed hemorrhagic tumors with luminal narrowing. Retrograde DBE demonstrated additional ileal and colonic lesions. Computed tomography showed small-bowel stenosis, mesenteric dissemination, bone metastases, and soft-tissue infiltration around an abdominal aortic stent graft. The patient died 7 weeks after transfer. Autopsy confirmed disseminated angiosarcoma involving the small intestine and mesentery, with the greatest tumor burden around the aortic graft, suggesting a possible periaortic origin. This case highlights the complementary roles of SBCE and DBE and provides rare clinicopathological correlation with autopsy findings.