Re: pituitary tumor
They class them as microadenomas - smaller than 10mm and macroadenomas - equal or larger than 10mm.
Size, however, does not always matter in in pituitary tumors. What matters is that hormones that they secrete.
Size only matters when they happen to be aggressive, which is unusual. They are usually small and stay that way, and usually benign (as in not cancerous) but if they secrete hormones, they can have a effect on the body ranging from mood issues to fatality, depending on the type.
I became disabled due to mine.