A lung nodule is a small growth in the lung. Also known as a “spot on the lung” or pulmonary nodule, it can be difficult to diagnose.
Nodules measure less than 3 centimeters, which is just a little over one inch. Doctors refer to larger growths as “masses.”
Types of Lung Nodules
There are two main types of nodules – benign and malignant. Benign nodules are non-cancerous while malignant nodules are cancerous. More than 90 percent of nodules smaller than 2 centimeters are benign, which means they will not spread to other parts of your body.
Lung infections are a common cause of benign pulmonary nodules. Three main types of infections can cause nodules to develop in the lungs:
- Bacterial infection – especially from tuberculosis
- Fungal infection – such as histoplasmosis, an infection by a fungus found in the droppings of birds and bats
- Parasitic infection – pneumocystis carinii pneumonia (PCP), a serious infection that causes inflammation and fluid buildup in the lungs, especially in patients with HIV/AIDS.
Other common causes of non-cancerous lung growths include granulomas and hamartomas. Granulomas are areas of inflamed or infected tissue that have hardened into a ball-like shape. Hamartomas are areas of tissue hardened by calcification or scarring.
Nodules may be the result of neoplasms, which are growths that may be cancerous or non-cancerous. Many things can cause benign growths, including:
- Fibroma, which is a lump of fibrous connective tissue
- Hamartomas, an abnormal grouping of normal tissues
- Neurofibroma, a growth made of nerve tissue
- Blastoma, a lump consisting of immature cells
Lung Nodule Testing and Diagnosis
Your doctor may suggest periodic checks and further testing, such as bronchoscopy or tissue biopsy, to determine if your nodule is cancerous if it grows or changes over time.
Our lung specialists at O2 Pulmonary & Sleep Group perform a variety of tests to determine the cause of lung nodules. A bronchoscopy is especially helpful in that it is a minimally invasive way to look inside your lungs. We use a bronchoscope for the procedure, which is a fiber-optic camera mounted on a long, flexible tube. In some cases, we take a small tissue sample from the nodule to send to the laboratory for testing.
Treatment is usually not necessary for benign pulmonary nodules, aside from treating the infection, inflammation or other underlying cause. Doctors may recommend removal of a malignant growth if the cancer has not spread to other organs.
Testing can take the worry out of having one or more lung nodules. Pulmonary tests can determine whether the growth in your lung is cancerous or benign, and taking the mystery out of your lung nodule can help you get a good night’s sleep.