Coronal section through both lungs viewed from behind, demonstrating a tumour arising from the right mainstem bronchus, which it narrows, with subcarinal nodal involvement. There is additional invasion into the adjacent lung parenchyma and tumour nodules are also present in the left lung.Histology was consistent with a small cell lung cancer. Author: Yale Rosen, M.D., original file here, modifications: square crop, license: Creative Commons Share alike 2.0