Are benign tumors in the lungs rare?

No: Benign lung nodules are not rare and are found during routine chest x-rays or, more likely ct scans. The most common are hamartomas or adenomas that are totally innocent if they are in the outer lung as usual but can block a lung if they are in one of the bronchial tubes. Although, pet scans can help determine that these are benign, some require surgical removal to assure that they are benign.