肺血管内的圆洞是脂肪栓子。脂肪栓塞最常发生于伴有长骨骨折的外伤，骨折脂肪细胞破裂释放脂肪滴进入血液循环中，脂肪滴进入肺毛细血管，逐渐产生类似于大鞍状血栓引起的肺动脉栓塞的后果。
The rounded holes that appear in the vascular spaces here in the lung are fat emboli. Fat embolization syndrome occurs most often following trauma with fracture of long bones that releases fat globules into the circulation which are trapped in pulmonary capillaries. Cumulatively, they have the same effect as a large saddle pulmonary embolus.
