A lung nodule is a disorder caused by abnormal growth that occurs in the lung. It is a prevalent type of infection that may develop in one or both lungs. The leading causes of pulmonary nodules are either infectious or neoplastic. It may also represent arteriovenous malformations, hamartoma, resolving pneumonia, and pulmonary infarction (Loverdos et al., 2019). Furthermore, other roots of the disease are scar tissue, air pollutants, fungal infection, and autoimmune illnesses. Symptoms of pulmonary nodule include fatigue, chronic cough, chest pain, wheezing, hoarseness, loss of appetite, and pneumonia. During the early stages, it is less likely to identify the signs of the lung nodule. According to Loverdos et al. (2019), lung nodules are detected nearly 150,000 times in a span of a year in the U.S. Sometimes, the condition and indications of the growth may suggest lung cancer.
Based on the result of CT imaging, lung nodules can be grouped into three classes; first, ground-glass, which are not uniform in their appearance but have an unclear local decrease in lung parenchyma that does not block the vascular structures. Second, solid nodules are marked by soft tissues which are similar in form (Gould et al., 2013). Third, part-solid nodule exhibits both ground-glass and solid characteristics. Based on the diameter of the rounded opacity, lung nodules with rounded lesions bigger than 3cm are defined as lung masses (Loverdos et al., 2019). According to Loverdos et al. (2019), lung masses could indicate lung cancer unless otherwise proved. The study conducted by McWilliams et al. (2013) defined that the nodule’s size has a nonlinear relationship with lung cancer, and nodules located in the upper lobes suggest increased cancer probability. The pulmonary nodule condition can either be multiple or solitary, whereby in the former, the nodule is bounded entirely by lung parenchyma (McWilliams et al., 2013). On the contrary, the latter consists of several nodules which are nonsolid.
Another significant characteristic of lung nodules is the risk of malignancy, which should be addressed in the evaluation and treatment processes. According to Gould et al. (2013), malignancy is common for nonsolid and part-solid nodules that develop a solid component. A strong predictor of malignancy is true cavitation, which implies walls’ irregular and thick character (Gould et al., 2013). Malignancy is more common among individuals over 65 years old and highest among smokers (Gould et al., 2013). Even though it is apparent that malignancy is more common among individuals with a high daily intake of tobacco, there is no definition of a harmless smoking threshold (Loverdos et al., 2019). The risks for different forms of tobacco intake, such as pipes and cigars, are not apparent, yet the risk of lung cancer from the use of electronic cigarettes is not researched yet.
The lung nodule diagnosis involves taking a CT scan to enable the pulmonologist to identify the shape, location, and size of the nodule. Other tests, such as biopsy, entail removing a piece of tissue from the body for closer examination. Similarly, a physician may conduct a positron emission tomography scan to analyze whether the pulmonary nodule is cancerous or non-cancerous because of the ability to have finer details. Computes-assisted techniques could be used to differentiate between malignant nodules with larger nodule sizes and benign nodules. Despite being rarely used in the United States, a dynamic CT scan is highly effective in identifying malignant nodules due to its dynamic contrast enhancement (Gould et al., 2013).
References
Gould, M. K., Donington, J., Lynch, W. R., Mazzone, P. J., Midthun, D. E., Naidich, D. P., & Wiener, R. S. (2013). Evaluation of individuals with pulmonary nodules: When is it lung cancer?: Diagnosis and management of lung cancer: American College of Chest Physicians evidence-based clinical practice guidelines. Chest, 143(5), e93S-e120S.
Loverdos, K., Fotiadis, A., Kontogianni, C., Iliopoulou, M., & Gaga, M. (2019). Lung nodules: A comprehensive review on current approach and management. Annals of thoracic medicine, 14(4), 226.
McWilliams, A., Tammemagi, M. C., Mayo, J. R., Roberts, H., Liu, G., Soghrati, K.,… & Lam, S. (2013). Probability of cancer in pulmonary nodules detected on first screening CT. New England Journal of Medicine, 369(10), 910-919.