What Does "sharply Circumscribed Cystic Structure" On An MRI Report Indicate?

I was diagnosed with a sharply circumscribed cystic structure adjacent to or involving the inferior aspect of the frontal horn of the left ventrical. My doctor said it was just a cyst and I would do an MRI every couple years to monitor. She said it is not the reason I have had migraines and nausea. Does this sound right?