Figure 1 Pre - and post- thrombolysis DSA findings   Anteroposteric DSA before thrombolysis showed the thrombus shadow in the M1 segment of the left MCA (arrow indicates, Panel 1a).   Immediate anteroposteric DSA after initial thrombolysis showed thrombus shadow in the M2 segment of the left MCA (arrow indicates, Panel 1b).   Lateral DSA after secondary thrombolysis showed recanalization of the left MCA occlusion (Panel 1c).   Anteroposteric DSA after secondary thrombolysis showed the left MCA was patency, and the thrombus shadow disappeared in the M1 and M2 segments of the left MCA (Panel 1d).

Figure 2 Light microscopy showed round, polygonal and stellate cells were observed with more mucous matrix and a few hyaline fibers.   HE staining  × 200

Figure 3 Postoperative CT findings showed a gradual decrease in the left basal ganglia density (arrows indicate).   Immediately after thrombolysis (Panel 3a).   The 2nd day after thrombolysis (Panel 3b).   The 7th day after surgery (Panel 3c).

Figure 4 Postoperative head FLAIR showed hyperintensity in the left basal ganglia, suggesting acute cerebral infarction (arrow indicates).

Figure 5 Postoperative echocardiography showed a slightly strong echo mass in left atrium, with a size of about 3.20 cm × 2.20 cm.

Figure 6 Light microscopy showed round, polygonal and stellate cells were observed in the postoperative resected mucus, surrounded by a large amount of loose matrix rich in acidic mucopolysaccharides.  HE staining  × 200