Image challenge: A rare cause of GI bleeding in a patient with a history of alcoholic cirrhosis

Gastroenterology clinical image challenge: A 45-year-old man who complained of a two-month history of intermittent gastrointestinal bleeding presenting hematochezia and weight loss, was admitted to our hospital. He had a medical history of alcoholic cirrhosis for three years. Physical examination revealed massive ascites and pale skin. Initial laboratory investigations showed a hemoglobin level of 67 g/L and serum levels of tumor markers were within the normal range. Repeated blood transfusions were required because of continued blood loss. The gastroendoscopy and colonoscopy found no esophageal varices and only an ulcerated lesion was observed and biopsied in the antrum (Figure). A computed tomographic scan of the abdomen (Figure) revealed that the small bowel wall was segmentally distributed, eccentric, thickened, and in the enhanced arterial phase they were obviously enhanced with multiple lymph nodes in the abdomen and retroperitoneal. Then an anterograde and retrograde single-balloon enteroscopy was administered, which demonstrated many segmentally distributed lesions ranging from the stomach to the distal ileum. These lesions — which included red dilated capillaries, ulcerated eminence lesions, and large exophytic masses measuring 2–3 cm scattered (Figure) — were causing massive overt gastrointestinal bleeding. Biopsies were taken from the friable lesions that bled with easy contact. 

The histopathology (Figure) revealed some irregular, anastomosing vascular channels lined by enlarged endothelial cells with epithelioid morphology. Immunohistochemical stains were positive for CD31 (Figure) and ERG, but negative for CD34, SMA, CD117, DOG-1, and S100, which consistent with epithelioid angiosarcoma.

What is the diagnosis?