Common causes of lung lesions, also known as solitary pulmonary nodules, include bacterial infections, such as histoplasmosis, gryptococcosis, tuberculosis, aspergillosis and coccidioidomycosis, according to Healthline. The leading cause of malignant lung lesions is lung cancer. In 20 to 30 percent of patients, lesions are the first indication of lung cancer.
Patients affected with bacterial infections may develop benign or noncancerous legions as a reaction to the infection, explains Healthline. In some cases, lung lesions develop as a result of scarring. A CT scan or chest X-ray often detects a lung lesion in the lungs. A physician may also perform a biopsy to determine if the lesion is cancerous, a condition also known as solitary coin lesion. Doctors recommend a biopsy if the patient smokes or displays symptoms of lung cancer, if the nodule has changed in appearance or size, and if the nodule, or lesion, is larger than 3 centimeters wide.
Individuals who have been exposed to carcinogens or those who smoke are more at risk of developing a lung lesion, too, according to Healthline. Lung lesions may also develop if cancer in another part of the body spreads to the lungs. If the lung lesion is determined to be noncancerous, treatment is not typically necessary.