Surgical therapy for hemangioma of the azygos vein arch under thoracoscopy: A case report

Figure 2 Hematoxylin and eosin staining. A and B: There were enlarged and dilated thin-walled blood vessels with intact endothelial cells on the wall, in which the medial muscle layer was thinned, and a large number of red blood cells were found outside the lumen (A: 40 ×; B: 100 ×); C and D: Multiple red blood cells were observed in the expanded blood vessel wall, composing the mural thrombus (C: 40 ×; D: 100 ×).