What Causes Lung Nodules
Lung nodules are masses of tissues found in the lungs; they are usually benign but can also be an indication of lung cancer. A more formal definition is, “a single lesion in the lung completely surrounded by lung parenchyma (functional tissue) with a diameter less than 3 cm and without associated pneumonia, atelectasis (lung collapse) or lymphadenopathies (swollen lymph nodes)”.
Mayo Clinic describes lung nodules as round, white shadows on a chest X-ray or computerized tomography (CT) scan, about 1/5 inch to 1 inch, or 5 millimeters (mm) to 25 mm, in size. A larger lung nodule, such as one that’s 25 mm or larger, is more likely to be cancerous than is a smaller lung nodule.
Lung nodules are also referred to as pulmonary nodules and in simplest terms appear as a spot on the lung. A spot that has a diameter of three centimeters or less is called a nodule. A larger spot is referred to as a mass and is treated differently when being diagnosed and evaluated. Usually smaller nodules (1cm or less) indicate a higher survival chance if the nodule is cancerous.
A benign pulmonary nodule does not go through much growth or change, however cancerous nodules tend to grow quickly; they may double their size every 25 to 120 days. A cancerous nodule appears as a sore that steadily spreads to more of the lung’s structures. This will eventually lead to shortness of breath, fatigue, and chest pain.
Causes of Lung Nodules
Non-cancerous nodules are typically healed over “wounds” on the lung left from inflammation caused by tuberculosis, a fungal infection or other similar condition. Cancerous nodules can be the first stage of a primary lung cancer, brought on by smoking or any other common cause of lung cancer. They also can be a secondary cancer that metastasized in the lungs from a primary cancer elsewhere in the body. Further causes of lung nodules are classified as inflammatory, congenital or neoplastic.
Histoplasmosis and Tuberculosis
Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum and primarily affects the lungs. Majority of persons infected with the disease do not usually experience any illness. However those that do experience symptoms will have a general ill feeling, fever, chest pains, and a dry or nonproductive cough. Chronic lung disease resembles tuberculosis and can worsen over months or years. The disseminated form is fatal unless treated. Tuberculosis is a chronic bacterial infection that primarily affects the lungs; it is contagious and is airborne.
Hematoma
A haematoma, or hematoma, is an abnormal collection of blood outside the blood vessels, generally the result of hemorrhage (internal bleeding). The blood is usually clotted or partially clotted and typically situated within an organ or a soft tissue space, such as a muscle.
Lung Cysts and Lung Cancer
Lung cyst describes the presence of a thin-walled, well-defined and well-circumscribed lesion in the lung, greater than 1 cm in diameter. Cysts may contain either air or fluid. Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. These abnormal cells do not carry out the functions of normal cells and do not develop into healthy lung tissue. As they grow, the abnormal cells can form tumors and impede the function of the lung, which is to provide oxygen to the body via the blood. Lung nodules are seen in the early stages of lung cancer.
