Given the variety of cell types that make up the lung and which may undergo pathological changes, numerous forms of cancer may result. When it appears in the epithelial cells of the bronchi, it is known as squamous cell lung cancer; in the alveoli, it generally appears as an adenocarcinoma.
肺部由各種不同細胞所組成，原始病變細胞不同，則肺癌的型態也不同，如由氣管上皮鱗狀細胞長出的癌症，稱為鱗狀細胞肺癌；從肺泡內皮長出的，則以腺癌居多。