Fig. 2

Histopathological findings. a Macroscopic findings: a light brown thrombus is visible in the pulmonary artery and dark red necrosis is visible in the peripheral pulmonary parenchyma. b Macroscopic findings: three layers of tissues (normal lung, intra-alveolar hemorrhage, and pulmonary necrosis layers) are visible from the proximal to the distal direction. c Microscopic findings: an organized thrombus is present in the pulmonary artery. Endothelial coverage, hyalinized fibrin, development of capillaries, and infiltration of fibroblasts are observed in the periphery of the thrombus, indicating its organization