Lung cancer and its associated tumor microenvironment and extensive field cancerizations. We can notice the local spread of the tumor microenvironment (TME) surrounding the tumor, consisting of various cellular populations (lymphocytes, neutrophils, macrophages, dendritic cells, fibroblasts, etc.). Adjacent to the TME, the cancerized field is associated with lung cancer, which diffusely extends upwards in the respiratory tract. The cancerized field can present various histologic changes, from hyperplasia to metaplasia and high-grade dysplasia, or might appear histologically normal, bearing only some focal genetic alterations.