Various Types Of Lung Cancer

There are basically two major types of lung cancer. These are known as small cell lung cancer and non small cell lung cancer. Details about these types of lung cancer, the sub-types, as applicable, and about one more type are provided below.

Small Cell Lung Cancer: This type gets its name from the shape of the cells which appear round and small when viewed under the microscope. It is also known as oat cell lung cancer. It occurs almost as a rule in heavy smokers and is rarer in its occurrence than non-small cell lung cancer.

Non-small cell lung cancer: This is a term used for a group of several types of lung cancers that are similar in their behavior. This group includes squamous cell carcinoma, large cell carcinoma, and adenocarcinoma.

Squamous cell carcinoma: This is the commonest form of lung cancer. It occurs in the airways lining cells.

Adenocarcinoma: This type of cancer develops from mucus producing cells that line the airways. Nowadays more people are afflicted with adenocarcinoma than earlier.

Large Cell Carcinoma: This type of lung cancer derives its name from the large round cells when examined under a microscope. It is also known as undifferentiated carcinoma.

There is one more type of lung cancer. It is known as Mesothelioma.

Mesothelioma: It is a cancer of the membrane (mesothelium) that covers the lungs, the chest, and the abdomen. The lining over the lungs is known as the pleura. Similarly, the peritoneum lines the abdomen. Mesothelioma is an uncommon cancer, which is now becoming more common.

The most common cause of mesothelioma is prolonged (10 to 60 years) exposure to asbestos. Most countries have therefore banned the use of blue or brown asbestos. However, sometimes asbestos is not the cause of mesothelioma. In such people, exposure to radiation has been suspected as its cause.

Pleural mesothelioma is twelve times more common than peritoneal mesothelioma.

Pleural mesothelioma: The lining around the lungs, the pleura, has two layers. The outer layer is known as the parietal layer and it lines the chest wall. The inner layer is known as the visceral layer and it lines the lungs. The two layers slide over each other during the process of breathing. Fluid produced by the membranes helps the sliding action.

When a pleural mesothelioma develops, these membranes thicken and press inward on the lungs. Pleural effusion or fluid collection between the two pleural layers may also occur.

Peritoneal Mesothelioma: The abdominal lining (the peritoneum) has two layers. The outer layer is adjacent the abdominal wall and is known as the parietal layer. The inner layer lines the abdominal viscera (organs) and is known as the visceral layer.

When the carcinoma afflicts the lining of the abdomen, it is known as peritoneal mesothelioma. It causes the membranes of the cavity to thicken and fluid collection in the abdomen. Such fluid collection is known as ascites and it causes the abdomen to swell.

If you can avoid exposure to cigarette smoke or to asbestos or to radiation, the chances of your being afflicted with any of the above types of lung cancer will be by far largely reduced.

Lung Cancer