Benign lung nodules and tumors generally cause no symptoms and are accidentally discovered on CT scans and chest X-rays, as stated by WebMD. If symptoms do occur, they may include shortness of breath, wheezing, coughing up blood, a lasting cough or fever, particularly when pneumonia is present.
A nodule appears as a spot on a CT scan or X-ray, and appears on approximately one in every 500 chest X-rays, as confirmed by WebMD. Although exact causes of benign lung tumors and nodules is not well understood, as of 2015, they may result from a lung abscess, an infectious fungus, tuberculosis, rheumatoid arthritis or round pneumonia.
To discover whether a lung tumor or nodule is benign or cancerous, a doctor may take the patient's medical history, perform a physical exam and take repeated X-rays for up to 2 years, according to WebMD. The tumor or nodule is considered benign if it stays the same size over this period, and it may also have a more even color and smoother edges than a cancerous nodule. The doctor may also use a tuberculin skin test, blood tests, magnetic resonance imaging or a biopsy to check for cancer. A nodule is more likely to be benign if it is small, possesses calcium, or if patient is under age 40 and does not smoke.