A lung mass may indicate lung cancer, an abscess, a form of pneumonia, a sign of infection or an amalgamation of protein, notes About.com. Lung masses are defined as abnormal spots in the lungs larger than 3 centimeters; those less than 3 centimeters in diameter are known as lung 'nodules.'
In addition to lung cancer, other cancers that show up as lung masses on imaging tests include sarcomas and lymphomas, and metastasized cancer from other parts of the body. Hamartomas -benign lung tumors- may appear as masses too, according to About.com.
In addition to tumors, such objects as lung abscesses, AV malformations, fungal and parasitic infections, lipoid pneumonia and aneurysms in the pulmonary artery also show up as masses on the lungs. When anomalous proteins build up to create a mass, the patient likely has a condition known as amyloidosis, states About.com.
While the majority of lung masses are cancerous, the wording in the lab report is crucial. Cancerous masses are often described as having a "ground glass" appearance, but if the words "calcifications" or "cavitary" show up, the tumor's likelihood of being benign is greater. In general, patients with a history of working in fields that exposed them to carcinogens or who have smoked have a higher chance of the mass being cancerous, as stated by About.com.