Fig. 1

a Ultrasound of the small intestine showing dilated intestinal loop and wall thickening (yellow arrow) as well as signs of intussusception (red arrow). b Contrast-enhanced computer tomography of the abdomen showing extensive wall thickening of the small intestine (yellow arrows) and short-segment invaginations. c Esophagogastroduodenoscopy showing fresh blood in the small intestine with no clear source of bleeding. d Biopsy was taken from the small intestine. e,f HE staining of the duodenal biopsy showing thrombotic microangiopathy with fibrin insudation in the vascular wall, endothelial swelling and fresh microthrombi leading to lumen obliteration (f shows magnification of marked area in e). g,h HE staining of the kidney transplant showing severe granulocytic-purulent and lymphoplasmatic interstitial nephritis. h In addition, signs of preglomerular arterial thrombotic microangiopathy in an artery with “onion-skin” lesion and entrapped erythrocytes and fragmentocytes