A pulmonary nodule is an abnormality in the lung that is smaller than 3 cm (slightly more than an inch) in diameter. Generally, a pulmonary nodule must grow to at least 1 cm (size of a pea) in diameter before it can be seen on a chest x-ray. CT scans can detect nodules less than 1 cm in size.
Pulmonary nodules are surrounded by normal lung tissue and are not associated with any other abnormality in the lung or nearby lymph nodes (small, bean-shaped structures found throughout the body).
Persons with a lung nodule or nodules do not experience symptoms.
Lung nodules are usually noticed by chance on a chest x-ray or CT scan taken for another reason(referred to as an incidental finding).
Lung nodules are one of the most common abnormalities seen on radiographic images.
Approximately 150,000 cases are detected every year as incidental findings, on x-ray films or CT scans.
Most lung nodules are benign (noncancerous); however, they may represent an early stage of primary lung cancer or they may indicate that cancer is metastasizing (spreading) from another part of the body to the affected lung.
Determining whether the lung nodule is benign or malignant is important. Prompt diagnosis and treatment of early lung cancer, presenting as a lung nodule, may be the only chance to cure the cancer.