An abnormal density in lung tissue may be caused by the presence of pulmonary nodules, which are characterized by their rounded appearance and small size. These irregular growths are typically detected during routine chest X-ray examinations or computerized tomography scans, notes Everyday Health.
The development of pulmonary nodules, particularly solitary lung nodules, is attributed to a broad range of possible causes, including neoplastic processes, infections, congenital defects and certain conditions. Solitary pulmonary nodules in lung tissue formed from neoplastic activities are either benign or cancerous. These abnormal densities include lung malignancy, metastatic cancer, carcinoid, lymphoma, fibroma, hamartoma, neurofibroma and blastoma. Sarcoma that occurs in the connective tissue of the lungs is also associated with solitary pulmonary nodules, states eMedicineHealth.
Infections that trigger an inflammatory response in the body are also likely causes of solitary lung nodules. These infections may be bacterial, fungal, viral or parasitic in origin, including tuberculosis, histoplasmosis, cryptococcosis, nocardiosis, coccidioidomycosis, blastomycosis, round pneumonia, lung abscess and hydatid cyst. Non-infectious inflammatory conditions, such as rheumatoid arthritis, sarcoidosis, lipoid pneumonia and Wegener granulomatosis, are also linked to the appearance of solitary lung nodules.
Congenital disorders, such as lung cyst, sequestration and arteriovenous malformation, also likely contribute to irregular growths in lung tissue. Other known causes of solitary pulmonary nodules include round atelectasis, pulmonary infarct, progressive massive fibrosis and overlap of the ribs, lymph nodes and blood vessels.