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Medical Content Created by the Faculty of the
Harvard Medical School

Large-Cell Carcinoma Of The Lung

What Is It?

Lung cancer (or carcinoma) is one of the most common cancers diagnosed in both men and women. There are two general categories of lung cancer, small cell lung cancer (SCLC) or non small lung cancer (NSCLC). There are several reasons for making the distinction between NSCLC and small cell lung cancer. The cancers appear differently when examined under the microscope. The early symptoms tend to be different. Treatment approach is different.

There are several varieties of non small lung cancer. These include large cell lung cancer, squamous cell lung cancer and adenocarcinoma of the lung.

While most lung cancers are directly related to cigarette smoking or other tobacco exposure, other chemicals and exposures to agents such as asbestos, radon, chromium, nickel and arsenic may be associated with the development of lung cancer.

Large cell carcinoma is the uncontrolled growth of abnormal cells in the lungs. This non-small cell lung cancer that represents 10% to 20% of all tumors that start in the bronchi, which are the main branches of the windpipe (trachea) that lead to the lungs. This type of lung cancer is associated strongly with smoking.

Large cell tumors are usually large at the time of diagnosis, although the term large in "large cell cancer" refers to the actual size of the cells as seen under the microscope. On chest x ray, large cell cancers of the lung are often located in the central portion of the lung. They tend to be accompanied by extensive bleeding and tissue damage. They often are called undifferentiated tumors because the cells lack the specific architecture found in other types of cancer cells. Large cell carcinoma tends to grow quickly and spread (metastasize) at an earlier stage than other forms of non-small cell lung cancer. In addition, many lung cancers may secrete unusual types of chemicals that circulate in the blood stream. Large cell lung cancer may secrete a substance that may actually cause enlargement of the male breasts, called gynecomastia. When cancers secrete chemicals that cause other portions of the body to react, this phenomenon is called a "paraneoplastic phenomenom."

The constant flow of fluids through the lungs can carry cancer cells to nearby parts of the body, such as the chest wall or the diaphragm. These fluids consist of blood and lymph (a protein filled fluid). Unless large cell carcinoma is diagnosed and treated early, it often spreads to organs outside of the chest area.