[Multifocal angiosarcoma of the gastrointestinal tract:a case report].

An 80-year-old man presented to our hospital with complaints of tarry stool and shortness of breath. A blood test confirmed marked anemia. On abdominal contrast-enhanced computed tomography, neither hemorrhagic lesions nor tumorous lesions could be pointed out. Upper gastrointestinal endoscopy revealed multiple erythematous flat elevated lesions, which were about 10mm in diameter, located between the stomach and the horizontal part of the duodenum. Colonoscopy revealed similar lesions throughout the entire colon. Pathological examination of biopsy specimens demonstrated the proliferation of neoplastic cells positive for immunostaining of factor VIII-related antigen, CD31, and CD34. Accordingly, the patient was diagnosed with angiosarcoma of the gastrointestinal tract. Although the patient was transferred to another hospital for chemotherapy, he died shortly after the transfer because of deterioration of his bleeding symptoms. Angiosarcoma is a soft-tissue neoplasm of vascular endothelium origin, accounting for less than 2% of all sarcomas. It usually occurs in the skin of the head and neck and in soft tissues. Angiosarcoma of the gastrointestinal tract is rare and is described only in case reports and small series. These tumors are characterized by an extremely aggressive course, with a high tendency to metastasize, leaving patients with a poor prognosis. When angiosarcoma is found in multiple sites of the gastrointestinal tract, it is sometimes difficult to differentiate between primary and metastatic occurrences. We analyzed reported cases of multifocal angiosarcoma of the digestive tract, of which there are 43 so far. In 24 cases, the angiosarcoma was thought to originate from the gastrointestinal tract (primary angiosarcoma). In 13 cases, angiosarcoma of other organs metastasized to the digestive tract (metastatic angiosarcoma). In the remaining 6 cases, whether the multifocal angiosarcoma of the digestive tract was primary or metastatic was unclear. In the current case, no primary lesion was found outside the gastrointestinal tract. Therefore, he was diagnosed with primary multifocal angiosarcoma.