What are nodules in lungs?

Updated March 23, 2017

Lung nodules, also known as pulmonary nodules, are round or oval lesions located in the lungs. The lesions can be benign, non-cancerous, or malignant, cancerous. According to Allen J. Blaivas, D.O., more than half of all lung nodules are benign. Though this is encouraging, there is also a risk of malignancy with pulmonary nodules.


There are several things that can contribute to the development of lung nodules. Previous infections can cause scarring which can lead to the development of benign lung nodules. Another leading cause of benign lung nodules are granulomas. Granulomas are small areas of inflamed lung tissue that, if left untreated, can develop into lesions. The most common cause of malignant lung nodules is lung cancer.

Risk Factors

Unfortunately, there are no symptoms of lung nodules. Due to the lack of visible symptoms, patients with certain risk factors may be monitored for evidence of lesions. Patients are at a greater risk of developing lung nodules if they have current or previous tuberculosis infections. The presence of a lung disease, such as histoplasmosis or cryptococcosis, can also increase your risk of developing lung nodules.


A lung nodule is usually found while testing for unrelated medical conditions. Typically, a lung nodule will be found during a chest x-ray. If a lung nodule is identified, a CT scan may be ordered for more detailed imaging of the lesion. Once the physician has reviewed the images a decision will be made as to the type of nodule that is present. If necessary, a biopsy can be performed to determine if the nodule is cancerous.


The decision on treatment will be based on the test results. A lung nodule will usually be removed if the CT scan or biopsy suggests the lesion is malignant.The patient's current health and lifestyle choices, such as smoking, are also taken into account prior to removal. If the physician decides to monitor the lesion, regular x-rays will be performed. If the lesion shows no growth and is believed to be benign, the lesion will not be removed.


The prognosis for lung nodules that are caught varies. For malignant nodules, the outlook is good once the malignant lesion has been removed. While the outlook may be good as far as the nodules are concerned, the concern going forward is focused on treating lung cancer if that was the primary cause of the malignant lesion. For those lesions being monitored, the outlook is also good. If there is no sign of growth in two years the lesion is defined as benign and it will not require further observation.

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About the Author

Nicole Long is a freelance writer based in Cincinnati, Ohio. With experience in management and customer service, business is a primary focus of her writing. Long also has education and experience in the fields of sports medicine, first aid and coaching. She earned her Bachelor of Arts degree in economics from the University of Cincinnati.