Small cell lung cancer is a disease in which malignant (cancerous) cells have formed in the lung tissue.
Lungs are a pair of cone-shaped breathing organs located in the chest cavity. When you breathe in, the lungs bring oxygen into the body. When you breathe out, the lungs release carbon dioxide, a waste product produced by the body’s cells. Each side of the lung is made up of lobes. The left lung has two lobes. The right lung is slightly larger than the left lung and has three lobes. Two ducts, called bronchi, start in the trachea and extend to the left and right lungs. Lung cancer can sometimes involve the bronchi. The inside of the lung is made up of tiny air sacs called alveoli and small tubes called fine bronchioles.
Chest x-ray. x-rays are used to take pictures of organs and bones of the chest. x-rays pass through the patient’s body and map the images onto film. onto the film.
CT scan of the brain, chest, and abdomen (CAT scan): A test that takes detailed images of a series of internal areas of the body from different angles. The images are generated by a computer that is connected to an x-ray machine. A contrast agent may be injected into a vein or swallowed to make the organs or tissues appear more clearly. This method is also known as computed tomography, computed tomography, or “computed axial tomography”.
Sputum cytology: Microscopy is used to find cancer cells in sputum (mucus coughed up from the lungs).
Biopsy: Cells or tissue are removed and examined by a pathologist under a microscope for signs of cancer. The different types of biopsies are shown below.
Fine needle aspiration (FNA) biopsy of the lung: A fine needle is used to aspirate tissue or fluid from the lung. A CT scan, ultrasound, or other imaging modality may be used to localize the abnormal tissue or fluid in the lung. A small incision is made in the skin through which the needle for the biopsy can be inserted into the abnormal tissue or fluid. The needle aspirates some of the sample that is sent to the laboratory. The pathologist can then look at the sample through a microscope and check for the presence of cancer cells. Finally, an x-ray is done to make sure no gas is leaking from the lungs into the chest cavity. 
Fine needle aspiration biopsy of the lungs. The patient lies on an exam table that passes through a computed tomography (CT) scanner, which takes x-rays of the inside of the body. x-rays help the doctor see the location of abnormal lung tissue. A biopsy needle is inserted through the chest wall and into the abnormal lung tissue area. A small piece of tissue is removed through the needle and examined under a microscope for signs of cancer.
Bronchoscopy: A procedure that looks through the airways and large airways of the lung to find areas of abnormality. A bronchoscope is inserted through the nose or mouth into the trachea as well as the lungs. A bronchoscope is a thin tube-like instrument with a lens and a light source on it for observation. It may also contain tools to remove tissue, and the removed tissue is examined under a microscope to look for signs of cancer. 
Bronchoscopy. A bronchoscope is inserted into the lungs through the mouth, trachea, and main bronchus to look for areas of abnormality. A bronchoscope is a thin tube-like instrument with a lens and a light source for visualization. It may also have tools for removing tissue. The removed tissue is examined under a microscope to look for signs of disease.
Thoracoscopy: A surgical procedure used to examine abnormal areas of organs inside the chest. An incision (opening) is made between two ribs and the thoracoscope is inserted inside the chest cavity. A thoracoscope is a thin tube-like instrument with a lens and light source for visualization. It also contains tools to remove tissue or lymph node samples, and the removed tissue is examined under a microscope to look for signs of cancer. In some cases, this method can also be used to remove parts of the esophagus or lungs. If a specific tissue, organ or lymph node cannot be reached, then open-heart surgery is performed. During this procedure, a large incision is made between the ribs and the chest cavity needs to be opened.
Thoracocentesis: A puncture needle is used to extract fluid from the lining of the chest cavity to the lungs. The pathologist looks at the fluid sample under a microscope to look for cancer cells.
Mediastinoscopy: A surgical operation to examine abnormal areas of organs, tissues, and lymph nodes between the lungs. An incision is made at the top of the sternum and the mediastinoscope is inserted into the chest from there. A mediastinoscope is a thin tube-shaped device with a light source and a lens for visualization. It may also have a tool that removes a sample of tissue or lymph nodes, and the removed tissue is examined under a microscope for signs of cancer.
Light and electron microscopy: A laboratory test that uses conventional and high-powered microscopes to look at cells in a tissue sample to look for certain changes in the cells.
Immunohistochemistry: A laboratory test that uses antibodies to look for certain antigens (markers) in a patient’s tissue sample. Antibodies are usually linked to enzymes or fluorescent dyes. After the antibody binds to a specific antigen in the tissue sample, the enzyme or dye is activated and the antigen can then be seen under a microscope. This type of test is used to aid in the diagnosis of cancer and to help distinguish between different types of cancer.
Some factors affect prognosis (likelihood of recovery) as well as treatment options.
Prognosis (chance of recurrence) and treatment options depend on the following factors:
Stage of the cancer (size of the tumor and whether it is confined to the lungs or has spread to other parts of the body).
The patient’s age, gender, and general health status.
For some patients, the prognosis also depends on whether the patient receives both chemotherapy and radiation therapy.
For most patients with small cell lung cancer, the current treatment options do not cure the cancer.
If lung cancer is detected, patients should consider participating in a clinical trial designed to improve treatment. Clinical trials for patients with various stages of small cell lung cancer are currently underway in many parts of the country. Information about ongoing clinical trials is available from the NCI webpage.