A fir tree has been found growing inside a man's lung by surgeons who were operating on him for suspected cancer.
The tree, measuring 5cm, was discovered by Russian doctors when they opened up Artyom Sidorkin, 28, to remove what they thought was a tumour.
Medical staff believe that Mr Sidorkin somehow inhaled a seed, which later sprouted into a small fir tree inside his lung.
http://www.dailymail.co.uk/news/worldnews/article-1169861/Shocked-Russian-surgeons-open-man-thought-tumour--FIR-TREE-inside-lung.html
so .... maybe we were all right as kids and we should we rethink that whole swallowing watermelon seed thing?