Diagnosis

Finding Lung Cancer Cells
Types of Lung Cancer

If you have a symptom that suggests lung cancer, your doctor must find out whether it's from cancer or something else. Your doctor may ask about your personal and family medical history. Your doctor may order blood tests, and you may have one or more of the following tests:

•· Physical exam: Your doctor checks for general signs of health, listens to your breathing, and checks for fluid in the lungs. Your doctor may feel for swollen lymph nodes and a swollen liver.

•· Chest x-ray: X-ray pictures of your chest may show tumors or abnormal fluid.

•· CT scan: Doctors often use CT scans to take pictures of tissue inside the chest. An x-ray machine linked to a computer takes several pictures. For a spiral CT scan, the CT scanner rotates around you as you lie on a table. The table passes through the center of the scanner. The pictures may show a tumor, abnormal fluid, or swollen lymph nodes.

Finding Lung Cancer Cells

The only sure way to know if lung cancer is present is for a pathologist to check samples of cells or tissue. The pathologist studies the sample under a microscope and performs other tests. There are many ways to collect samples.

Your doctor may order one or more of the following tests to collect samples:

•· Sputum cytology: Thick fluid (sputum) is coughed up from the lungs. The lab checks samples of sputum for cancer cells.

•· Thoracentesis: The doctor uses a long needle to remove fluid (pleural fluid) from the chest. The lab checks the fluid for cancer cells.

•· Bronchoscopy: The doctor inserts a thin, lighted tube (a bronchoscope) through the nose or mouth into the lung. This allows an exam of the lungs and the air passages that lead to them. The doctor may take a sample of cells with a needle, brush, or other tool. The doctor also may wash the area with water to collect cells in the water.

•· Fine-needle aspiration: The doctor uses a thin needle to remove tissue or fluid from the lung or lymph node. Sometimes the doctor uses a CT scan or other imaging method to guide the needle to a lung tumor or lymph node.

•· Thoracoscopy: The surgeon makes several small incisions in your chest and back. The surgeon looks at the lungs and nearby tissues with a thin, lighted tube. If an abnormal area is seen, a biopsy to check for cancer cells may be needed.

•· Thoracotomy: The surgeon opens the chest with a long incision. Lymph nodes and other tissue may be removed.

•· Mediastinoscopy: The surgeon makes an incision at the top of the breastbone. A thin, lighted tube is used to see inside the chest. The surgeon may take tissue and lymph node samples.

Types of Lung Cancer

The pathologist checks the sputum, pleural fluid, tissue, or other samples for cancer cells. If cancer is found, the pathologist reports the type. The types of lung cancer are treated differently. The most common types are named for how the lung cancer cells look under a microscope:

•· Small cell lung cancer: About 13 percent of lung cancers are small cell lung cancers. This type tends to spread quickly.

•· Non-small cell lung cancer: Most lung cancers (about 87 percent) are non-small cell lung cancers. This type spreads more slowly than small cell lung cancer

Staging

Stages of Small Cell Lung Cancer
Stages of Non-Small Cell Lung Cancer

To plan the best treatment, your doctor needs to know the type of lung cancer and the extent (stage) of the disease. Staging is a careful attempt to find out whether the cancer has spread, and if so, to what parts of the body. Lung cancer spreads most often to the lymph nodes, brain, bones, liver, and adrenal glands.

When cancer spreads from its original place to another part of the body, the new tumor has the same kind of cancer cells and the same name as the original cancer. For example, if lung cancer spreads to the liver, the cancer cells in the liver are actually lung cancer cells. The disease is metastatic lung cancer, not liver cancer. For that reason, it's treated as lung cancer, not liver cancer. Doctors call the new tumor "distant" or metastatic disease.

Staging may involve blood tests and other tests:

•· CT scan: CT scans may show cancer that has spread to your liver, adrenal glands, brain, or other organs. You may receive contrast material by mouth and by injection into your arm or hand. The contrast material helps these tissues show up more clearly. If a tumor shows up on the CT scan, your doctor may order a biopsy to look for lung cancer cells.

•· Bone scan: A bone scan may show cancer that has spread to your bones. You receive an injection of a small amount of a radioactive substance. It travels through your blood and collects in your bones. A machine called a scanner detects and measures the radiation. The scanner makes pictures of your bones on a computer screen or on film.

•· MRI: Your doctor may order MRI pictures of your brain, bones, or other tissues. MRI uses a powerful magnet linked to a computer. It makes detailed pictures of tissue on a computer screen or film.

•· PET scan: Your doctor uses a PET scan to find cancer that has spread. You receive an injection of a small amount of radioactive sugar. A machine makes computerized pictures of the sugar being used by cells in the body. Cancer cells use sugar faster than normal cells, and areas with cancer look brighter on the pictures.

Stages of Small Cell Lung Cancer

Doctors describe small cell lung cancer using two stages:

•· Limited stage: Cancer is found only in one lung and its nearby tissues.

•· Extensive stage: Cancer is found in tissues of the chest outside of the lung in which it began. Or cancer is found in distant organs.

The treatment options are different for limited and extensive stage small cell lung cancer. See the Treatment section for information about treatment choices.

Stages of Non-Small Cell Lung Cancer

Doctors describe non-small cell lung cancer based on the size of the lung tumor and whether cancer has spread to the lymph nodes or other tissues:

•· Occult stage: Lung cancer cells are found in sputum or in a sample of water collected during bronchoscopy, but a tumor cannot be seen in the lung.

•· Stage 0: Cancer cells are found only in the innermost lining of the lung. The tumor has not grown through this lining. A Stage 0 tumor is also called carcinoma in situ. The tumor is not an invasive cancer.

•· Stage IA: The lung tumor is an invasive cancer. It has grown through the innermost lining of the lung into deeper lung tissue. The tumor is no more than 3 centimeters across (less than 1 ¼ inches). It is surrounded by normal tissue and the tumor does not invade the bronchus. Cancer cells are not found in nearby lymph nodes.

•· Stage IB: The tumor is larger or has grown deeper, but cancer cells are not found in nearby lymph nodes. The lung tumor is one of the following (see the picture of the main bronchus and pleura):

•· The tumor is more than 3 centimeters across.

•· It has grown into the main bronchus.

•· It has grown through the lung into the pleura.

•· Stage IIA: The lung tumor is no more than 3 centimeters across. Cancer cells are found in nearby lymph nodes.

•· Stage IIB: The tumor is one of the following:

•· Cancer cells are not found in nearby lymph nodes, but the tumor has invaded the chest wall, diaphragm, pleura, main bronchus, or tissue that surrounds the heart (see the picture of the diaphragm).

•· Cancer cells are found in nearby lymph nodes, and one of the following:

•· The tumor is more than 3 centimeters across.

•· It has grown into the main bronchus.

•· It has grown through the lung into the pleura.

•· Stage IIIA: The tumor may be any size. Cancer cells are found in the lymph nodes near the lungs and bronchi, and in the lymph nodes between the lungs but on the same side of the chest as the lung tumor.

•· Stage IIIB: The tumor may be any size. Cancer cells are found on the opposite side of the chest from the lung tumor or in the neck. The tumor may have invaded nearby organs, such as the heart, esophagus, or trachea. More than one malignant growth may be found within the same lobe of the lung. The doctor may find cancer cells in the pleural fluid.

•· Stage IV: Malignant growths may be found in more than one lobe of the same lung or in the other lung. Or cancer cells may be found in other parts of the body, such as the brain, adrenal gland, liver, or bone.

The detection of the lung cancer is done by screening of the suspected individuals, suspected individuals mean people who are indulged in smoking or people more than the age of 45. There is no change in the survival rate as a result of practicing screening of the suspected individuals by many government and international health organizations but one thing is clear patients who had gone under the screening and were diagnosed lung cancer most of them were asymptomatic. 

Once the diagnosis has been made on the basis of radiological screening and symptoms the next step taken is tissue diagnosis. Tissue diagnosis includes biopsy of the tumor tissue, biopsy of mediastinal lymph nodes and biopsy of bone lesions if present. The most important task of the pathologist is to differentiate between the types of lung cancer. There are two types of lung cancer small cell and non small cell.