I struggled with a similar situation in recent years. I asked on Mumsnet as I didn’t feel it was a subject I could bring up with anyone in real life.
This was a man who claimed to have a brain tumour and convinced the entire community. He even pre booked and arranged his funeral.
He had two biopsies (he said) to confirm the stage of the cancer. The first supposed biopsy he was dropped off at hospital and said he didn’t want anyone to visit him. His entire head had been shaved one length, and no shorter length for the biopsy site. No dressing as he said it had healed in the two weeks he had been absent.
He wore a dressing after his supposed second biopsy, but again, after removal, his hair (shaved all over entire head again) was the same length as before, and hadn’t been shaved to scalp on the biopsy site.
He would frequently fall and have fits, and make random noises, to act out his illness, and was helped by people, but he always got drunk beforehand.
He was also still driving around in his car in the midst of all this. Nobody questioned why he was allowed to do this.
We wondered how he would get out of this, and he came up with the story of being misdiagnosed (they missed it during two biopsies 🤔). Apparently it was just a cyst, though that cyst could burst at any time so he’s not allowed to wear tight head gear, like a helmet, for instance.
I can’t believe so many people fall for it and think he’s unwell. It’s damaged the mental health of his family, and he told his young children. A truly awful man.