The case concerns a 41-year-old man with recurrent gastrointestinal bleeding and secondary anemia requiring multiple blood transfusions, with protracted and increasing weakness. Physical examination revealed both flat and protruding, bluish skin lesions, fading under pressure, with a slightly wrinkled surface in the perioral area, forearms and the left knee. In addition, postsurgical deformation of the right foot was found due to skin lesion excision in childhood. In laboratory tests a low level of Hg 3.9 g/dl and iron deficiency were present. In the endoscopic examination of the gastrointestinal tract, numerous, bluish submucosal lesions were found in the esophagus, stomach (Fig. 1B), duodenum, small and large intestines (Fig. 1A). The size of the lesions was estimated to range from 0.2 mm to 4 cm. The patient was treated locally endoscopically and surgically and also received empiric chemotherapy without significant clinical improvement. The reemergence of new changes was observed. Histopathological biopsies revealed wide vascular spaces, thin-walled, lined with a single layer of endothelial cells with no atypia located within the submucosa of the gastrointestinal tract (Fig. 2 A-D, Fig. 3A). There were signs of fibrosis and hyalinosis in the surrounding tissue. The mucosa above the lesions revealed no significant pathological changes. Immunohistochemistry of vascular spaces’ lining: SMA+ CD34+, GLUT1– (Fig. 3B-D).