Hamartoma - Wikipedia
https://en.wikipedia.org/wiki/HamartomaAbout 5–8% of all solitary lung nodules and about 75% of all benign lung tumors, are hamartomas. They almost always arise from connective tissue and are generally formed of cartilage, connective tissue, and fat cells, although they may include many other types of cells. The great majority of them form in the connective tissue on the outside of the lungs, although about 10% form deep i…