Lung cancer? Naw. It's honestly probably a muscle knot, and at worst, a cyst. Think about this. To get permanent lung damage, you have to smoke a pack of cigarettes a day for 10 years before there is enough damage that your body can't overcome. Also, people that end up getting lung cancer from smoking, smoke a pack a day for up to 40 to 45 years!! Of course, there are things other than lung cancer, such as COPD which can show up at this time too. My point is not to encourage smoking, but to indicate to you just how resilient our bodies are.
Think about it....a pack of cigarettes a day for 40 years...do you know how many cigarettes that is?!!!