There are several types of cancer of the lung, distinguished by the appearance down the microscope. The commonest type of lung cancer is changing; whereas squamous carcinoma accouned for up to half of all cases in the 1970's, adenocarcinoma is increasing in incidence and has overtaken squamous histology as being the most common histological sub-type in some countries at present.Large cell carcinoma accounts for 10-15% of the total.
There is a particular subtype called small cell cancer, which is important to recognise separately from the other types as management varies from the general principles that apply for all the other types. Also called ‘oat’ cell carcinoma (because the cells look oat seed shaped down the microscope and under the high power lens) small cell cancers account for 20% of the total numbers of lung cancer. Rare types are giant cell carcinoma and the truly lung (as distinct from bronchial) alveolar cell carcinoma.
