Her personality, aggression and cognitive changes started last January. She recently had a baseball sized mass removed, after refusing a D and C a few months ago. She has a POA that is a failure at helping, as she lives several hundred miles away. Seems like neglect of an elder, but what can be done?
She has been making changes in her will more than once since this started, and changed her bank accounts and made POA changes. This just cannot be normal!
You should have a Come To Jesus meeting with the POA, who if it’s one of her children, could be having cognitive issues also.
https://www.agingcare.com/questions/elder-placed-a-pfa-against-the-family-member-who-has-cared-for-them-473674.htm
You say she is making changes to POA and accounts and wills. In the case of POA and wills she would be examined by an attorney for competency with each change she makes. Hopefully she is seeing that all accounts have a POD (pay on death) beneficiary, OR is listed in her papers and has beneficiaries listed in her will.
No, a uterine tumor is not known for causing changes in mentation. The two are likely unrelated.
I am uncertain your relationship to this person in familial connection or in terms of locale, or your need to know in this instance, nor even your questions, other than any possible connection between mentation and tumor (which is unlikely). As you are not her POA there may be no issues you need to address.
There may of course be worries about any diagnosis, any surgeries planned, aftercare, ongoing issues in future, and there is likely to be a good deal of anxiety for this woman, which often can look quite a lot like dementia in some people and at some times.
Am wishing her the best.