Lung Cancer Diagnosis
Lung cancer diagnosis - Physical examination and initial tests
If the patient's doctor suspects lung cancer, he or she will take a detailed medical
history to check all the symptoms and assess the risk factors. The history-taking will be
followed by a complete physical examination. The doctor will examine the patient's throat
to rule out other possible causes of hoarseness or coughing, and listen to the patient's
breathing and the sounds made when the patient's chest and upper back are tapped
(percussed). The physical examination, however, is not conclusive.
If the doctor has reason to suspect lung cancer-- particularly if the patient has a
history of heavy smoking or occupational exposure to substances that are known to irritate
the lungs-- he or she may order a chest x ray to see if there are any masses in the lungs.
Special imaging techniques, such as CT scans or MRIs, may provide more precise information
about the size, shape, and location of any tumors.
Lung cancer diagnosis -Sputum analysis
Sputum analysis involves microscopic examination of the cells that are either coughed
up from the lungs, or are collected through a special instrument called a bronchoscope.
Sputum analyses can diagnose at least 30% of lung cancers, some of which do not show up
even on chest x rays. In addition, the test can help detect cancer in its very early
stages, before it spreads to other regions. The sputum test does not, however, provide any
information about the location of the tumor and must be followed by other tests.
Lung cancer diagnosis -Lung biopsy
Lung biopsy is the most definitive
diagnostic tool for cancer. It can be performed in several different ways. The doctor can
perform a bronchoscopy, which involves the insertion of a slender, lighted tube, called a
bronchoscope, down the patient's throat and into the lungs. In addition to viewing the
passageways of the lungs, the doctor can use the bronchoscope to obtain samples of the
lung tissue. In another procedure known as a needle biopsy, the location of the tumor is
first identified using a CT scan or MRI. The doctor then inserts a needle through the
chest wall and collects a sample of tissue from the tumor. In the third procedure, known
as surgical biopsy, the chest wall is opened up and a part of the tumor, or all of it, is
removed. A doctor who specializes in the study of diseased tissue (a pathologist) examines
the tumor samples to identify the cancer's type and stage.
Lung cancer diagnosis -Blood Tests
If a chest x-ray or sputum cytology proves inconclusive, blood tests may be
ordered. These tests look for substances in the blood that suggest the possibility of
tumors. These tests include the PTH (parathyroid hormone) test, the CEA (carcinogenic
antigen) test, and the CYFRA 21-1 (cytokeratin 19 fragment) test. A positive result from
any of these blood tests indicates the possibility of lung tumors.
Lung cancer diagnosis -Diagnostic Imaging
If a biopsy result proves positive, the next step is to determine the stage and spread
of the cancer. A number of diagnostic imaging tools may be used to do so.
CAT Scan (Computed Tomography): A CAT scan (also known as a CT scan), uses a
combination of computer technology and chest x-rays to generate detailed images of the
internal organs.
MRI (Magnetic Resonance Imaging): An MRI scan uses a powerful magnet and radiowaves
to generate a computer image of the lungs. The MRI signals vary depending on the nature of
the scanned cells.
Other forms of diagnostic imaging, such as radionuclide scanning and bone scans, check if
the malignant cells have metastasized and spread to other organs. The stage and spread of
lung cancer determines what the treatment options are.
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