I actually have been smelling what I call cigarette smoke smell. This has been going on and off since I was 12. I hadn't smelled it for a few years and hadn't been bothered by it, it started a few months ago. I would get it once a month about for only a few minutes, then a few weeks ago it was almost every 3rd day and the episodes went up to a few hours. Once my sinuses started acting up I added that to the mix and found...yes, Brain Tumor. I completely went insane, I went to my doctor who told me that it was part of the sinus infection. I told him that it had been there way before the infection, he didn't really seem to care that much. Now I'm in the same boat, I don't know what to do and I feel like a fool going back...let me know what you've found out.