Squamous-Cell Carcinoma Of The Lung

What Is It?

Squamous-cell carcinoma of the lung accounts for about 30 percent of cases of non-small-cell lung cancer. Most squamous-cell carcinoma originates in the central portions of the lungs. These tumors may cause symptoms of coughing up blood at an earlier stage than tumors located on the edges of the lungs (such as the more common adenocarcinoma).

Squamous-cell carcinoma often spreads (metastasizes) to other parts of the body because of the constant flow of fluids (blood and lymph) through the lungs. The fluids can carry cancer cells to adjoining structures, such as the chest wall, the neck, esophagus or heart. Unless the cancer is diagnosed and treated early, it frequently becomes a systemwide, rather than local, disease. Outside of the chest, lung cancer commonly spreads to the bones, brain, liver and adrenal glands.

Symptoms

Although some cancers initially have no symptoms, others are diagnosed during an evaluation for any of the following:

• A persistent cough
• Coughing up of blood (hemoptysis)
• Unexplained weight loss or loss of appetite
• Shortness of breath or wheezing
• Fatigue
• Increased mucus secretions or phlegm coughed from the lungs
• Difficulty swallowing
• Pain in the chest, shoulder or arm
• Recurrent pneumonias in the same place
• Bone pain
• Hoarseness
• Headaches, confusion or seizures
• Swelling of the face, neck or upper extremities
• Enlargement of the ends of fingers and toes (digital clubbing)

Diagnosis

Squamous-cell carcinoma often is discovered on a chest X-ray, on which it appears as a dark, shaded area. Other imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI), may be used to further determine the size, shape and location of the tumor. This helps to find the best place to obtain a sample of the tumor to diagnose squamous cell versus other types of lung cancer such as small-cell carcinoma or adenocarcinoma of the lung. The type of cancer affects what treatment you should get. The tumor also can spread to the lung from another organ outside of the chest.

Another way to diagnose the tumor type is with sputum cytology, in which mucus from the lungs (sputum) is examined under a microscope to check for abnormal cells. Cancer cells also can be found in fluid between the lung and the chest wall (requiring a thoracentesis procedure using a needle to remove pleural fluid) or in lymph nodes next to the lung (requiring a mediastinoscopy surgical procedure).