Lung cancer cell. Coloured scanning electron micrograph (SEM) of a lung cancer cell from an adenocarcinoma. Adenocarcinoma is a non-small cell lung cancer that is more commonly found in women and non-smokers, and it is the most common type of lung cancer for people under 45. Unfortunately, the incidence of adenocarcinoma of the lung is on the increase in the UK and it is now one of the most common types of lung cancer. Adenocarcinoma accounts for approximately 50% of all non-small cell lung cancers and begins in the outer sections of the lung (although it can occur as central lesions) which can make it difficult to detect in the early stages of the disease. It develops from lung cells that produce mucus and, unlike many other types of lung cancer, it is more likely to remain in one area giving better opportunities for treatment. Magnification: x3000 at 10 centimetres wide.