Interesting! It was a medium tumour so it was caught quite early!
As Kaycee says, any roller coaster shudders and jolts. The biology of tumours varies so much, so I havn't a single clue how it dislodged, but I can be sure that the motion of a roller coaster effects every part of your body quite substantially.
They say riding a roller coaster increases your blood pressure to hypertensive levels, scary! Excess cranial pressure caused by g-force or movement could have also affected the tumour.
The best, most informed enthusiast EVER!!111