Cancerous tumours of the lung

A cancerous tumour of the lung can grow into nearby tissue and destroy it. The tumour can also spread (metastasize) to other parts of the body. Cancerous tumours are also called malignant tumours.

There are 2 main types of lung cancer: non−small cell lung cancer and small cell lung cancer.

Non–small cell lung cancer is the most common type of cancerous tumour of the lung. About 80% to 85% of lung cancers are non–small cell lung cancer.

There are many different subtypes of non–small cell lung cancer that start in the different types of cells and tissues of the lung.

Adenocarcinoma is the most common type of non–small cell lung cancer. It starts in the lung cells that make mucus. Adenocarcinoma tumours are often found in the outer edges of the lungs. This type of tumour is more likely to be found before it has started to spread to other parts of the body.

There are many different subtypes of adenocarcinoma, such as solid, papillary, and mucinous adenocarcinoma. The names are based on what the cells look like when viewed with a microscope, the types of patterns that the cells are in, and whether or not the cells have mucus in them.

Diagnosis, staging and treatment are similar for the different types of adenocarcinoma.

Squamous cell carcinoma is the second most common type of non–small cell lung cancer. It starts in the flat cells that line the airway tubes of the lung (bronchi).

There are different subtypes of squamous cell carcinoma. They are given names based on what the cells look like when viewed with a microscope, the types of patterns that the cells are in and other features.

Diagnosis, staging and treatment are similar for the different types of squamous cell carcinoma.

Large cell carcinoma has tumours with cells that look very large and round when examined under a microscope. It is a very rare type of non-small cell lung cancer. It can grow and spread very quickly.

Sometimes lung cancer cells look undeveloped when examined under a microscope. The type of non−small cell lung cancer can't be identified, so these tumours are called undifferentiated tumours.

Small cell lung cancer is usually in the centre of a lung. It is called small cell because the cancer cells look small when they are examined under a microscope.

Small cell lung cancer is the most aggressive type of lung cancer. In many cases it has already spread to other parts of the body when it is diagnosed.

The main types of small cell lung cancer are small cell carcinoma and combined small cell carcinoma (mixed tumour with squamous or glandular cells).

Neuroendocrine tumours can start in the neuroendocrine cells in the lung. Neuroendocrine cells receive messages (signals) from the nervous system and respond by making and releasing hormones, which are substances that control many body functions. Types of neuroendocrine lung tumours include typical and atypical carcinoid tumours.

Find out more about lung neuroendocrine tumours( lung NETS).

Superior pulmonary sulcus tumours are named for where they are found, in the upper rounded part of the lung. They are most often squamous cell carcinoma, but they can also be adenocarcinoma tumours. Because of where the cancer is growing, superior pulmonary tumours are more likely to grow into the chest wall, rather than into the lung tissues. They can spread to nerves, ribs and the bones of the spine.

Mesothelioma is a type of cancer that starts in the membranes that cover most of the organs in the body. It often starts in the pleura, which is the membrane that covers the lungs.

Find out more about mesothelioma.

Lung metastases are cancerous tumours that have spread to the lung from another part of the body. The lung is one of the most common places where other cancers spread. Almost any kind of cancer can spread to the lung.

For example, breast cancer often spreads to the lung. But this is not lung cancer − it is breast cancer with lung metastases. It would be treated like breast cancer, not like a cancer that started in the lung.

Find out more about lung metastases.