Ron was told that he had a pea seed in his lung that had split and had sprouted. It was probably about half an inch which is a pretty big thing. Ron said: ‘‘whether this would have gone full-term and I’d be working for the Jolly Green Giant, I don’t know. But, I think the thing that finally dawned on me is that it wasn’t the Cancer”. His relieved wife even added that “God has such a sense of humour. I mean it could have been just nothing, but it had to be a pea, and it had to be sprouting.” 

Earlier another incident took place where a 28 year old named Artyom Sidorkin from Russia was assumed to have Cancer but later the test results revealed that it was actually a 5 centimetre fir tree growing in his lungs which had to be removed by surgery.
[source:mnn]