Found out my mom is faking cancer

99% sure my mom is faking having cancer (anonymously posted in case anyone I know or she knows is on here) she's saying that the cancer she has makes sense and is connected to people with, or relatives of, my chronic illness. Called my specialist panicked and he told me that there has never been any link between the cancer and this illness because they are 100% different with no connecting factors. I don't know how to cope. She's lied about our family cancer history in the past and is a notorious liar for pity... But lying about actively having cancer is just... Way more than I thought she was capable of...
I'm pretty sure now that she's a sociopath. Help? Words of support?
EDIT: she told me that the doctor point blank asked her about if anyone in her family has my chronic illness by name. When I told this to my specialist he said that no real doctor would even mention my illness because there is absolutely no connection.