Benign tumors VERY RARELY develop into metastatic (cancerous or spreading) tumors.
Most of them are treatable by removing it and usually don't reoccur after removal.
Their therapy is important, cause they can lead to brain and nerve damage due to compression.
What other symptoms you have along with headaches?

Look up vitamin b17. Its in apricot seeds and actually kills cancer. Im not sure how well it works with non cancerous tumors, I recall reading that the molecule kills the cancerous part of the tumor only, leaving a small noncancerous mass behind (percentage of tumor which wasn't cancerous). SO seeing that you're worried your noncancerous brain tumor could become cancerous, I would start researching into vitamin b17 and apricot seeds. It will prevent it. Theres a lot of suppressed info in a book called... World Without Cancer by G.E. Griffin