肺动脉大分支内的肺血栓栓子。淡红色及红色的指状突区域形成血栓的特征Zahn线。这些线代表数层细胞，包括红细胞层，血小板层及纤维蛋白层，它们以血栓的形式存在于血管内。
This is the microscopic appearance of a pulmonary thromboembolus in a large pulmonary artery. There are interdigitating areas of pale pink and red that form the "lines of Zahn" characteristic for a thrombus. These lines represent layers of red cells, platelets, and fibrin which are layed down in the vessel as the thrombus forms.
